fast rak building designer fundamentals

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Building Designer

Fundamentals

1 2013 Version 15 June

Contents 1.0 Introducing Fastrak Building Designer ....................................................................................... 7

1.1 Example Structures ........................................................................................................................................................... 9

1.2 Program Scope ................................................................................................................................................................ 10 1.2.1 Fastrak Building Designer Suite ...................................................................................................................................... 10 1.2.2 Modelling ........................................................................................................................................................................ 10 1.2.3 Design ............................................................................................................................................................................. 10 1.2.4 Building Design ............................................................................................................................................................... 10 1.2.5 Automatic Links .............................................................................................................................................................. 10

1.3 Screen Layout.................................................................................................................................................................. 11

1.4 Tutorial Building .............................................................................................................................................................. 12 1.4.1 Tutorial Building Drawings .............................................................................................................................................. 12 1.4.2 Design Data ..................................................................................................................................................................... 13

2.0 Constructing the design model ................................................................................................ 15

2.1 Starting a New Project .................................................................................................................................................... 17 2.1.1 Screen Layout.................................................................................................................................................................. 17

2.2 Construction Levels and Gridlines .................................................................................................................................. 18 2.2.1 Modelling theory for this tutorial example..................................................................................................................... 18 2.2.2 Construction Levels ......................................................................................................................................................... 18 2.2.3 Creating Gridlines ........................................................................................................................................................... 19 2.2.4 Additional Gridlines ........................................................................................................................................................ 23 2.2.5 Customising Grid Lines .................................................................................................................................................... 24

2.3 View Options ................................................................................................................................................................... 25 2.3.1 The View Options Window ............................................................................................................................................. 25

2.4 The Structure-3D View .................................................................................................................................................... 25 2.4.1 The 3D View .................................................................................................................................................................... 25 2.4.2 Structure-3D View – The View Tool Bar .......................................................................................................................... 26 2.4.3 Structure-3D View – The Scheme Tool Bar ..................................................................................................................... 26 2.4.4 Sharing Gridlines ............................................................................................................................................................. 28

2.5 Dimensions and Measurements ..................................................................................................................................... 31 2.5.1 Creating Dimensions ....................................................................................................................................................... 31 2.5.2 Deleting Dimensions ....................................................................................................................................................... 31 2.5.3 Grids Measure Command ............................................................................................................................................... 32 2.5.4 Grids Measure Angle ....................................................................................................................................................... 32

2.6 Structural Elements ........................................................................................................................................................ 33 2.6.1 Simple Construction ........................................................................................................................................................ 33 2.6.2 Attribute Sets .................................................................................................................................................................. 33 2.6.3 Creating Structural Elements .......................................................................................................................................... 34

2.7 Columns .......................................................................................................................................................................... 35 2.7.1 Simple Column Attribute Set .......................................................................................................................................... 35 2.7.2 Creating Columns ............................................................................................................................................................ 37 2.7.3 Deleting Columns ............................................................................................................................................................ 38

2.8 Modifying Structural Elements ....................................................................................................................................... 41 2.8.1 Individual Structural Building Objects Properties. .......................................................................................................... 41 2.8.2 Modification using the Properties Window .................................................................................................................... 42 2.8.3 Applying an Attribute Set ................................................................................................................................................ 43

2.9 Beams ............................................................................................................................................................................. 45


2.9.1 Simple Beam Attribute Set ............................................................................................................................................. 45 2.9.2 Creating Beams ............................................................................................................................................................... 47 2.9.3 Creating Beams by Area ................................................................................................................................................. 48 2.9.4 Creating Beams Singularly – Between Grid Intersections .............................................................................................. 49 2.9.5 Creating Beams Singularly – Coordinated off other Beam Positions .............................................................................. 50 2.9.6 Copying Elements ........................................................................................................................................................... 52 2.9.7 Create Infill Beams .......................................................................................................................................................... 54 2.9.8 Creating Beams at Absolute Distances ........................................................................................................................... 57

2.10 Grouping ......................................................................................................................................................................... 61 2.10.1 Creating Groups and Sub-groups ............................................................................................................................... 62 2.10.2 Using Groups to Edit Properties ................................................................................................................................. 67 2.10.3 Selection Group Filter................................................................................................................................................. 67

2.11 Copy Elements ................................................................................................................................................................ 68

2.12 More Grids, Columns and Beams ................................................................................................................................... 71 2.12.1 Sharing and Modifying Gridlines ................................................................................................................................ 71 2.12.2 Creating More Columns ............................................................................................................................................. 74 2.12.3 Creating More Beams ................................................................................................................................................. 74

2.13 Slabs ................................................................................................................................................................................ 75 2.13.1 Composite Slab Attribute Set ..................................................................................................................................... 75 2.13.2 Creating Slabs - by Group ........................................................................................................................................... 77 2.13.3 Changing Slab Orientations ........................................................................................................................................ 80 2.13.4 Adding New Slab Groups ............................................................................................................................................ 81 2.13.5 Final Slab Floor Plan ................................................................................................................................................... 81

2.14 Validating the Structure.................................................................................................................................................. 83 2.14.1 Staged Modelling and Design ..................................................................................................................................... 83 2.14.2 Validating ................................................................................................................................................................... 83 2.14.3 Element Reference Names ......................................................................................................................................... 83 2.14.4 Finding Elements with Validation Issues .................................................................................................................... 84

2.15 General Beam & Columns ............................................................................................................................................... 85 2.15.1 Cantilever General Beam ........................................................................................................................................... 85 2.15.2 Modifying Beam Properties ....................................................................................................................................... 85 2.15.3 Simple Columns .......................................................................................................................................................... 87 2.15.4 General Columns ........................................................................................................................................................ 87 2.15.5 Modifying Column Properties .................................................................................................................................... 88

2.16 Simple Columns with Cantilever Simple Beams ............................................................................................................. 89 2.16.1 Simple Beam Cantilever ............................................................................................................................................. 89 2.16.2 Simple Column Restraints .......................................................................................................................................... 89

3.0 Load cases and combination.................................................................................................... 91

3.1 Load Cases ...................................................................................................................................................................... 93 3.1.1 Loading Toolbars ............................................................................................................................................................ 93 3.1.2 Load Types ...................................................................................................................................................................... 93 3.1.3 Tutorial Model Load Cases ............................................................................................................................................. 94 3.1.4 Creating Load Cases ........................................................................................................................................................ 94 3.1.5 Creating a Floor Load ...................................................................................................................................................... 96 3.1.6 Creating Other Slab Loads .............................................................................................................................................. 98 3.1.7 Creating Element Loads ................................................................................................................................................ 100 3.1.8 Modifying Loads ........................................................................................................................................................... 102 3.1.9 Deleting Loads .............................................................................................................................................................. 103

3.2 Load Combinations ....................................................................................................................................................... 105 3.2.1 Defining Combinations ................................................................................................................................................. 105

4.0 Performing a gravity design ................................................................................................... 109


4.1 Design Options .............................................................................................................................................................. 111 4.1.1 Design Control .............................................................................................................................................................. 111 4.1.2 Force limits - Members ................................................................................................................................................. 112

4.2 Analysis Options ............................................................................................................................................................ 113 4.2.1 Analysis ......................................................................................................................................................................... 113

4.3 Performing a Design and Design Results ...................................................................................................................... 114 4.3.1 Workspace Window ...................................................................................................................................................... 114

4.4 Show / Alter State Options ........................................................................................................................................... 115 4.4.1 Design Status ................................................................................................................................................................ 116 4.4.2 Moment Releases ......................................................................................................................................................... 116 4.4.3 Alter Diaphragm ............................................................................................................................................................ 117 4.4.4 Show Diaphragm ........................................................................................................................................................... 118 4.4.5 Wall Surface .................................................................................................................................................................. 118 4.4.6 Report Level .................................................................................................................................................................. 118 4.4.7 Integration Status ......................................................................................................................................................... 118

5.0 Lateral movement under gravity loading ............................................................................... 119

5.1 Validity of the Gravity Design Results ........................................................................................................................... 121 5.1.1 Maximum Nodal Deflections ........................................................................................................................................ 121

5.2 Resistance of Lateral Movement .................................................................................................................................. 122 5.2.1 Methods Used to Resist Lateral Movement. ................................................................................................................ 122 5.2.2 Diaphragm Action of Floors .......................................................................................................................................... 122

5.3 Applying Diaphragm Action to a Floor .......................................................................................................................... 123 5.3.1 Reset Auto Design Mode .............................................................................................................................................. 123

5.4 Creating Frame Views – 2D Elevations ......................................................................................................................... 124 5.4.1 Proposed Arrangement of the Vertical Bracing ............................................................................................................ 124

5.5 Vertical Bracing ............................................................................................................................................................. 126 5.5.1 Creating Bracing Attribute Sets..................................................................................................................................... 126 5.5.2 Creating Bracing Elements ............................................................................................................................................ 126

5.6 Tension Only Bracing .................................................................................................................................................... 128 5.6.1 Analysis and Design Theory .......................................................................................................................................... 128 5.6.2 Setting Braces as In-active ............................................................................................................................................ 129 5.6.3 Revised Max Nodal Deflection Check ........................................................................................................................... 130

6.0 Design and Analysis Results .................................................................................................. 131

6.1 Loading Summary Tables .............................................................................................................................................. 133

6.2 Individual Elements Design and Results ....................................................................................................................... 134 6.2.1 Results via the Workspace Window.............................................................................................................................. 134 6.2.2 Example Results for a Simple Beam .............................................................................................................................. 135 6.2.3 Example Results for a General Beam ............................................................................................................................ 135

6.3 Graphical Results – Right-Click Options ........................................................................................................................ 136 6.3.1 Analysis Results ............................................................................................................................................................. 138 6.3.2 Reports .......................................................................................................................................................................... 139

6.4 Graphical 3D Model Analysis Options ........................................................................................................................... 141 6.4.1 Output Graphics Toolbar .............................................................................................................................................. 141 6.4.2 Diagram Scaling............................................................................................................................................................. 142 6.4.3 Changing the Analysis Output Colours.......................................................................................................................... 143 6.4.4 Displaying Extreme Analysis Values on the 3D diagram ............................................................................................... 143 6.4.5 Example Analysis 3D Diagrams ..................................................................................................................................... 144

7.0 Adding Upper Storeys ........................................................................................................... 145


7.1 Adding Duplicate Floors ................................................................................................................................................ 147 7.1.1 Creating Additional Construction Levels ...................................................................................................................... 147 7.1.2 Copying Floors .............................................................................................................................................................. 148 7.1.3 Extending Columns ....................................................................................................................................................... 149 7.1.4 Copy Bracing Elements to the Upper Storeys ............................................................................................................... 150

7.2 Completing the Gravity Design ..................................................................................................................................... 152

8.0 Frame Imperfections and Sway ............................................................................................. 153

8.1 Imperfections and Sway Introduction .......................................................................................................................... 155 8.1.1 Notional Horizontal Forces ........................................................................................................................................... 155

8.2 Practical Imperfections ................................................................................................................................................. 155

8.3 Sway Sensitivity Analysis. P-Delta Effects ..................................................................................................................... 156 8.3.1 Local p-delta buckling (p ............................................................................................................................................ 156 8.3.2 Global P-Delta buckling (P ......................................................................................................................................... 156 8.3.3 Sway or None Sway Susceptibility and Evaluation of cr Results.................................................................................. 157 8.3.4 Non Sway Sensitive Frames (cr > 10) .......................................................................................................................... 157 8.3.5 Sway Sensitive frames (4 < cr < 10) ........................................................................................................................... 157 8.3.6 The Amplified Moments Method, the Kamp Approach. ................................................................................................. 158 8.3.7 Second Order Analysis required (cr < 4) .................................................................................................................... 158 8.3.8 Options for Automatically Applying Kamp ...................................................................................................................... 158

8.4 Creating Notional Horizontal Forces ............................................................................................................................. 159 8.4.1 Calculating NHF’s .......................................................................................................................................................... 159 8.4.2 Creating Combinations with NHF’s ............................................................................................................................... 159

8.5 Design Results for Frame Imperfections ....................................................................................................................... 160

8.6 Determination of Sway Sensitivity ................................................................................................................................ 161 8.6.1 Viewing the Sway Results ............................................................................................................................................. 161 8.6.2 Sway X Critical ............................................................................................................................................................... 162 8.6.3 Sway Y Critical ............................................................................................................................................................... 162

8.7 Automatic Application of Kamp ...................................................................................................................................... 163 8.7.1 Setting the Auto-Kamp Formula Method ..................................................................................................................... 163 8.7.2 Applying the Auto-Kamp ................................................................................................................................................. 163

8.8 Sway Results ................................................................................................................................................................. 165

9.0 Reports and Drawings ........................................................................................................... 167

9.1 Reports ......................................................................................................................................................................... 169 9.1.1 Show Alter State Graphical Method ............................................................................................................................. 169 9.1.2 Workspace Report Area ................................................................................................................................................ 170 9.1.3 Report Content ............................................................................................................................................................. 172 9.1.4 Element Reports ........................................................................................................................................................... 173 9.1.5 Exporting Results to Excel ............................................................................................................................................. 175 9.1.6 Material Listing ............................................................................................................................................................. 177

9.2 Drawings ....................................................................................................................................................................... 178 9.2.1 DXF Plans and Elevations .............................................................................................................................................. 178 9.2.2 3D Model ...................................................................................................................................................................... 180

9.3 Export Options .............................................................................................................................................................. 181

10.0 Lateral Loading ..................................................................................................................... 183

10.1 Lateral Wind Loading .................................................................................................................................................... 185

10.2 Variable Lateral Loading Possibilities............................................................................................................................ 186 10.2.1 Wind Nodal Point Loads ........................................................................................................................................... 186 10.2.2 Element Loading ....................................................................................................................................................... 186


10.2.3 Roof’s Applying and Adjusting .................................................................................................................................. 187 10.2.4 Application of Area Loading to Roofing Elements .................................................................................................... 188 10.2.5 Applying Wind Walls and Using the Wind Load Generator ...................................................................................... 189

10.3 The Simple Wind Load Generator ................................................................................................................................. 192 10.3.1 Application of nodal loads ........................................................................................................................................ 192 10.3.2 Wind load Generator ................................................................................................................................................ 193 10.3.3 Creating Wind Loading Combinations and Re-evaluating the Structure .................................................................. 195

11.0 Composite Floor Design ........................................................................................................ 197

11.1 Composite Floor ............................................................................................................................................................ 199 11.1.1 Creating a Composite Beam Attribute Set ............................................................................................................... 201 11.1.2 Applying the Attribute Set ........................................................................................................................................ 202

11.2 Validation Issues ........................................................................................................................................................... 204

11.3 Composite Design Results ............................................................................................................................................. 207 11.3.1 Failing Beams ............................................................................................................................................................ 208

11.4 Rectifying the Design Model ......................................................................................................................................... 211 11.4.1 Degree of Shear Connection ..................................................................................................................................... 211 11.4.2 Design Results after Adjustment of Studs ................................................................................................................ 213 11.4.3 Considering Longitudinal Shear ................................................................................................................................ 215 11.4.4 Copy Attributes Tool ................................................................................................................................................. 218

11.5 Instances when Composite Design Cannot be Achieved .............................................................................................. 219 11.5.1 Validity of Design Results ......................................................................................................................................... 220

11.6 Overview of Stud Layout Options ................................................................................................................................. 221

12.0 Design Codes ........................................................................................................................ 225

12.1 Design Codes - Introduction. ........................................................................................................................................ 227 12.1.1 Access to the various design codes. ......................................................................................................................... 227 12.1.2 To set the default design code. ................................................................................................................................ 227 12.1.3 To change the current design code (but leave the default design code unaffected) ............................................... 228

12.2 British Standard (BS) Based Design. .............................................................................................................................. 229

12.3 American Institute of Steel Construction (AISC) Based Design. .................................................................................... 229

12.4 Eurocode (EC) Based Design. ........................................................................................................................................ 229

13.0 Creating an inclined roof structure ........................................................................................ 231

13.1 Introduction .................................................................................................................................................................. 233

13.2 Creating the Apex Construction Level........................................................................................................................... 234

13.3 Extending the Columns to the new Apex level ............................................................................................................. 234

13.4 Creating the new hip end steel roof beams. ................................................................................................................. 234

13.5 Creating Roof Items ...................................................................................................................................................... 235

13.6 Adjusting the Roof Item Span direction ........................................................................................................................ 236

13.7 Loading the Roof ........................................................................................................................................................... 238

14.0 Summary .............................................................................................................................. 239

14.1 Summary ....................................................................................................................................................................... 241 14.1.1 GENERAL MEMBERS AND CONTINUITY .................................................................................................................... 241 14.1.2 ADVANCED 3D MODELLING ..................................................................................................................................... 241 14.1.3 FURTHER ANALYSIS AND DESIGN ............................................................................................................................. 241

7

Introducing Fastrak Building Designer Example Structures

2013 Version 15 June

1.0 Introducing Fastrak Building Designer

Program scope and tutorial model

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Introducing Fastrak Building Designer Example Structures


1.1 Example Structures

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Introducing Fastrak Building Designer Program Scope


1.2 Program Scope

1.2.1 Fastrak Building Designer Suite

The main application is Fastrak Building Designer, the suite also includes the following modules:

BS-EC Wind Modeller, Portal Frame Design, Connection Design, Simple Beam, Composite Beam, General Beam, Simple Column and General Column

These individual modules can be used to investigate individual structural elements, by exporting them from the 3D model

These individual modules are not required to run the Fastrak Building Designer program

1.2.2 Modelling

Simple Creation of 2D or 3D input of floors and frames for rapid building creation.

Create any arrangement of grid lines to help you input the structure quickly and efficiently.

Importation of DXF drawings from AutoCAD, which can be either used as gridlines for the model creation or as a template on to which you can create your own gridlines.

No limitation in geometry or orientation for model creation.

All structural elements are handled as design objects not analysis elements.

Complex roofing structures, trusses, inclined members and floors can all be modelled in Fastrak Building Designer.

Diaphragm action of floors.

Lateral stability can be achieved with, rigid bays, plan and vertical bracing. With vertical bracing being in the form of X, A, >, /, K etc.

General Members can be any material specified by the user.

Various load types including, Floor, Area, Patch, Line, Concentrated, nodal and element loading.

Directional wind loading distribution

1.2.3 Design

Simple, composite and general construction for beams and columns. Assorted decking and slab types ranging from pc planks to profile metal decks.

Continuous construction for beams, with concrete filled columns and simple and moment columns.

Use of standard rolled, plated, Fabsec, ASBs, slim floor and Westok beams.

Options for web openings and nominal or fixed bases.

Lateral stability options in the form of rigid fixed bays, concrete shear walls, plan or vertical bracing.

1.2.4 Building Design

Detailed design to BS 5950 and/or AISC 360-05 and a range of supporting documents.

The engineer should be fully aware of the scope of operation so that he/she is aware of the design carried out by the software and what is currently beyond the scope of the software.

Detailed design output or design summaries for submission to checking authorities, in Microsoft Word.

Beam end reactions, material listings and base reactions in Microsoft Excel Format.

Automatic detailed design drawings of plans and elevations, including beam end reactions, span directions, floor slab and beam reinforcement.

1.2.5 Automatic Links

Structural elements from the design model can be individually investigated by exporting to the Fastrak design modules.

Portal frames can be modelled within Fastrak Building Designer, exported to the Fastrak Portal Frame design suite where they can be fully designed, with the resulting sections exported back to Fastrak Building Designer.

Fully functional analytical model available with export out to S-FrameTM and other structural analysis packages.

DXF output for 2D design drawings

3D DXF output of the 3D model.

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Introducing Fastrak Building Designer Screen Layout


3D models can be exported to 3D modelling systems such as 3D+ and Revit Structure.

SDNF (steelwork detailing neutral file) output for passing models to steelwork detailing software.

Direct link into fabrication software FabtrolTM

Creation of beam design files for Westok and Fabsec beams.

1.3 Screen Layout

The initial installation will create a standard screen setup as shown above. All windows and icons can be customised by the user and can be placed and docked at various positions on the screen. As can be seen above a new window called the properties window has been created where the user will be able to quickly refine and control the design model. All commands in Building Designer can be accessed either from the drop down menus or the icons on the screen. By hovering over any icon, the process for that icon can be established, a tool tip with more information is shown on the screen.

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Introducing Fastrak Building Designer Tutorial Building


1.4 Tutorial Building

1.4.1 Tutorial Building Drawings

Isometric View

Plan view

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Introducing Fastrak Building Designer Tutorial Building


1.4.2 Design Data

Tutorial Building Description

The tutorial building example is essentially 2 rectangular areas consisting of a 2 x 9m bay by 2 x 6 m bay in X and Y directions. These are cranked at an angle of 45 degrees with interconnecting structural members. 3 storeys of 4.00 m with a composite floor design in one half of the building

Secondary Steel at 3rd

points

External perimeter beams are simple in construction

Internal primary and secondary beams – Composite in Construction

Off Grid columns as shown

Loading Information

Self Weight – the only loadcase calculated by FTBD = Automatically Applied

Slab Wet (Total dead Load in the Construction stage) = 3 kN/m2

Slab Dry ( Total dead load in the final stage) = 2.5 kN/m2

Construction Live = 1 kN/m2

Imposed = 2.5 + 1 kN/m2

Various Dead Loading

Perimeter loading = 14kg/m3 x 0.14m (block width) x 4m storey height = 7.84kN/m ~ 8kN/m

Wind Loading on South and West Elevations = 1 kN/m2

Composite Data

Slab Depth = 150mm, Concrete Grade = 30N/mm2, Reinforcement (slab) = Mesh A142 throughout

Decking = RLSD AL, Gauge = 0.9mm

Standard Stud Layout, Stud Height = 100 mm

Steel Grade For Composite Beams = S355

Steel Grade For Simple Beams = S275

“e” distance information = 50mm

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Constructing the design model Tutorial Building


2.0 Constructing the design model

Creating grids, column, beams and slabs

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Constructing the design model Starting a New Project


2.1 Starting a New Project

Launch Building Designer and select “File / New Project” or press “New Project Icon”

A dialog box will appear on the screen asking you to fill out the project details for the model you are about to create. The Job Number is highlighted in red and the OK button is greyed out. Building Designer requires more information or numerical input before you can proceed out of this dialog box.

Enter the project information as shown below and press the “Ok” button.

2.1.1 Screen Layout

When the Ok button is pressed, the main workbook and the icons become active and a Structure-3D and Base-2D plan view of the base level are created as tabs above the main workbook. You will also notice that the Project workspace pane and the Properties pane will have also become active.

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Constructing the design model Construction Levels and Gridlines


2.2 Construction Levels and Gridlines

2.2.1 Modelling theory for this tutorial example

Before any structural element can be placed in Fastrak Building Designer a node is required to be created within the model.

For nodes to be created, intersecting gridlines on plan have to be created and shared with floor levels established on elevation.

In the construction of a multi-storey building, usually one of the floors is reproduced or used as a template. Therefore a recommendation that we have is that we model the first floor of the building initially and pass the pre-design check of validation. Then use that floor as a source template to create the rest of the structure. This is the Construction method we will be using in constructing the tutorial building model.

2.2.2 Construction Levels

Select “Building” from the drop down menus and then select “Levels“ or in the “Workspace” window double click on the title “Construction Levels”

The following dialog box will be displayed

From this dialog you can control the number of stories in your model, if the level is a floor and if diaphragm action is to be taken into account on that floor. Controls for imposed load reductions on specific floors can also be specified.

As you can see, Fastrak Building Designer already has two pre-defined construction levels of Base and Roof at a height of 0 and 3 metres respectively.

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2.2.3 Creating Gridlines

You can define grid lines quickly and simply in Fastrak Building Designer. Alternatively you can import them into your model from a DXF file. If you are importing grid lines from DXF files, please ensure that:

grid lines you are using are accurate,

the DXF file you are importing only contains grid lines. If you are in doubt we advise you to use Building Designer's ability to import a DXF file and create a shadow image of the structure. You can then add your Building Designer grid lines on top of the shadow DXF image.

Rectangular Grid Wizard

Fastrak Building Designer requires intersection points to place structural elements upon. Therefore, in the Base-2D workbook view we will create the gridlines required for the model. These gridlines will also be shared throughout the levels of the model i.e will co-exist on all other levels.

Two types of automated grid generation options exist, one for Rectangular Grids and another for Radial Grids

Click on the “Rectangular Grid“ icon to invoke the Rectangular Grid Wizard in the base view

The first dialog will ask you for the Origin position for the grid and the mouse pointer will change to display the coordinate positions on the screen.

Set the orthogonal grid origin position of “X=0, Y=0 “ either by graphically clicking on the screen, or entering values in the pop up dialog box and then press “Next>”

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The next dialog will ask you about the Direction of gridlines you wish to generate and the line style you wish to use.

Enter the information below and press “Next>”.

The next dialog will establish the extents of the grid in the X direction. Also in this dialog box you can establish the lettering or numbering of the generated gridlines, along with the direction of placement in relation to the global UCS position. It is possible to specify a Regular or Irregular arrangement of gridlines. In the X direction we will specify Regular.


The next dialog will establish the extents of the grid in the Y direction.

Selecting the Irregular option allows you can enter in absolute values, using a comma as a separator. For example 6,2,5,4 (m) or 3x6 for 3 bays at 6m.


The next two dialog boxes are used to set the Rotation and the Axis Angle of the grid layout relative to the Global X and Y co-ordinates.

Set the Grid Rotation angle at “0 degrees” and click “Next>”.

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Set the Axis Angle to “90 degrees” to have a perpendicular grid arrangement and click “Finish”.

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The Grid Arrangement should be as shown below.

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2.2.4 Additional Gridlines

The Grids Toolbar

Hover over the icons to display a tooltip and review the additional Grid commands available. These are; Grid Line, Grid Line Polar, Grid Line Parallel, Grid Line Perpendicular, Grid Arc and Share New Grids (which is depressed by default on the Base-2D level so that any grids created on the Base-2D level are replicated on all other levels in the model).

Placing Additional Gridlines

From the “Grids” drop down menu or from the Grid toolbar, select “Grid Line Parallel”. The following dialog will appear on the screen.

Building Designer requires a Base Line (reference line), from which a new parallel grid line is measured from. The operation of placing a gridline in the model can be performed graphically or by inputting values in the dialog box.

Click on “Grid Line B”, or select Grid Line B from the drop down menu in the dialog box.

Now either enter the distance “1.5m “ in the dialog box or graphically establish the distance by moving the mouse pointer and clicking at the required distance (this will place the value in the Distances box).

Once the value is specified in the dialog box press “Create” or Enter to place the Grid Line.

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2.2.5 Customising Grid Lines

Grid Line Properties

The rectangular grid wizard automatically labels the horizontal grid lines as numbers and the vertical grid lines as letters. When we added our additional parallel grid line the labelling on that grid line was automatically labelled as number “8” – This was because it was the 8

th grid line created in the model.

Subsequent gridlines would be labelled according to this sequence 9,10,11 etc.

To change the properties of any Grid Lines we need to be able to Select that object.

We will re-reference Grid Line “8” to “Ba”

From the Select toolbar depress the “Select” icon and from the Objects toolbar depress the “Grid” icon.

Left click on Grid Line 8 on the Base-2D workbook (the selected gridline will turn blue)

Now look at the Properties window and you will see properties for the selected gridline

Change the label from “8” to the new name “Ba” by clicking in the box and overwriting with the value required.

Now you change further grid line properties which include: 1. Label Name 2. Position of the Label View on the ends of the grid line 3. Line Type Style 4. If the individual line is hidden or not (Visible) 5. If the individual line is Selected or not 6. Whether the grid line is Shared throughout the rest of the levels in the structure.

The selected grid line will remain selected until we clear it from the selection set. On the Select toolbar left click the “Clear Selection” icon.

When no objects of the current object type are selected the clear selection icon is inactive (greyed out).

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Constructing the design model View Options


2.3 View Options

2.3.1 The View Options Window

When you have several structural objects on the screen, together with their text labels and rendering style you may find that the model display becomes cluttered and difficult to use. Fastrak Building Designer allows you to configure exactly what is, and what is not displayed in the current workbook view.

“Right click” at any position in the “workbook screen” and select “View Options” or select View Options ( “Properties”) from the “Navigation Tool Bar”.

In the View options dialog box review items and un-check those you do not want to display.

Close view options using the small red cross.

Note. It is possible to hold down CTRL and scroll the wheel mouse when the View Options dialog is active to alter the transparency level. This allows you to leave the dialog permanently visible and to see through it to the workbook window behind.

2.4 The Structure-3D View

2.4.1 The 3D View

A Structure-3D view has already been created for you as a tab above the main workbook window. If this was deleted however, it is possible to recreate this Structure-3D view by double clicking on the “Structure” label in the Project pane window.

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Constructing the design model The Structure-3D View


Obtain a Structure-3D view. A screen view will be created displaying a front view of the model by default.

2.4.2 Structure-3D View – The View Tool Bar

Hover over the icons to display a tooltip and review the View commands available. These are; Zoom Area, Zoom Node, Zoom All (2D views only), Front, Back, Left, Right, Top and Bottom View (3D views only), View South-East, South-West, North-East, North-West (3D Views only). Move, Pan and Zoom and Info Level.

2.4.3 Structure-3D View – The Scheme Tool Bar

Hover over the icons to display a tooltip and review the Scheme commands available. These are; Axis, Wireframe and Solid when viewing static views. Bounding Box, Axis, Wireframe and Solid when dynamically reviewing structure. Isometric or Perspective View (3D views only) and Animate to rotate the 3D view (3D views only).

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With the icons as shown on the Scheme toolbar above the building will be shown as a Full Solid Rendering and then will be seen as a axis (wire-frame) view when the building is moved or rotated

Use View Options to turn on the Axis and Axis Name from the Grid tab.

Choose an isometric view – View South-West

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2.4.4 Sharing Gridlines

What is Sharing Gridlines?

The final icon on the grids toolbar is the option to share new grids. With this option selected any gridlines placed at any particular level are duplicated throughout the structure. When an intersection of gridlines is created between levels, a black square box will appear denoting that the gridlines are shared.

With gridlines that are shared between levels, it is then possible to place columns vertically between the floors in a 2D plan view. The dialog box below appears when columns are created in 2D mode with more than 2 storeys to allow you to specify the column start and end levels.

Using the Workspace and Properties Window

Workspace Window

When a gridline is created, it is placed in the workbook area (main screen) and given a number depending on the number of gridlines placed in the model. With this gridline in the model it is also referenced and logged in the Project Pane window under the floor name in which the gridline is placed.

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By finding the gridline reference and right clicking, more options are available such as visible, selected and shared.

Properties Window

Using the Selection tool and the Grids Building Objects, unshared gridlines can be selected and displayed in the Properties window. Again within the properties window you have options as described above with the associated gridline where sharing is available.

Note – Remember to always clear your selection afterwards.

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Constructing the design model


Shared Gridlines in the 3D Structure view

When a shared gridline is displayed in the structure view a vertical gridline is displayed to shown that it is shared between levels.

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Constructing the design model Dimensions and Measurements


2.5 Dimensions and Measurements

2.5.1 Creating Dimensions

A linear dimension can be measured and shown on the screen either on plan in the 2D view or in elevation or inclination in the structure views.

Press the “Create” button on the Edit toolbar and then select “Dimension” from the Object toolbar.

Then select two intersection points on the base floor layout to define the start position and end position of measurement. Move the mouse to define an offset for the placement of the dimension and finally undertake a third click to place.

Dimensions can be created on both 2D and 3D views.

Note – to undertake a running dimension hold the CTRL key down whilst placing.

2.5.2 Deleting Dimensions

Any unwanted dimensions that you have created can be deleted by conducting the following operation.

Pick “Delete” from the edit toolbar and the “Dimension” from the building objects one.

Now delete any unwanted dimensions by graphically picking them on the screen.

Any Structural element can be deleted in the same manner in any of the views plan, elevation or structural 3D view

When you are deleting any structural object in Fastrak Building Designer, place the mouse pointer over the object and you will notice that the mouse pointer will change shape and the object that is about to be deleted will become highlighted.

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Constructing the design model Dimensions and Measurements


2.5.3 Grids Measure Command

The Measure command can be used in any 2D or 3D view

Select “Measure” from the “Grid” drop down menu

Pick a node on the model

Then move the mouse pointer to any other intersection point and the screen the total distance and the coordinates in x, y, z (depending what view you are in) will be displayed graphically.

To change the reference point, click on any other node in the model.

2.5.4 Grids Measure Angle

The Angle command can be used in any 2D or 3D view. The operation is performed in a similar method as the measure command.

Select “Measure Angle” from the “Grid” drop down menu.

Select a reference Grid Line to measure from.

Then move the mouse pointer to any other gridline and graphically on the screen the horizontal or inclined angle we be displayed. (depending what view you are in)

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Constructing the design model Structural Elements


2.6 Structural Elements

The main Structural Elements that can be placed in Fastrak Building Designer are:

Columns (Simple Columns, General Columns or Gable Posts)

Beams (Simple Beams, General Beams or Composite Beams)

Slabs (Slabs, Roofs)

Bracings

General Members and Curved Beams (Cannot be Designed only Modelled)

2.6.1 Simple Construction

The most effective design for a multi storey structure is still likely to be simple beams and columns with bracing to resist the lateral forces. Simple construction in BS 5950 implies certain types of modelling and certain specific design rules (both inclusions and exclusions). We assume your familiarity with these. We recommend that you use Simple beams and columns where possible. Building Designer will happily design moment frames or continuous beams automatically within a model, but the design of these elements is much more comprehensive (and hence takes longer). For this reason you should only use such elements when your model specifically requires them. When you use simple columns they are pinned at every floor level (except where they are connected to a braced bay) to ensure that all lateral load is transferred to the braced bay. This modelling is in line with the SCI guidelines in the Steel Designers Handbook. You may pin or fix general columns at each floor level as you wish.

2.6.2 Attribute Sets

Each structural element that you place in Building Designer will have a set of criteria; these criteria are known as Attributes.

Attribute Sets can be pre-defined for any structural element, with several Attribute Sets for each element type.

The Attributes list is located in the Project workspace pane. Click on the plus sign to expand the attributes list then click on the plus sign next to the column and you will see that Fastrak Building Designer has a predefined attribute already set for you.

It is important to realise that the Attribute Sets are used to set up defaults for the elements (beams, columns... ...) in your model. The Attribute Sets are NOT linked to the elements once they are created.

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Constructing the design model Structural Elements


2.6.3 Creating Structural Elements

The procedure Fastrak Building Designer uses to manipulate any structural element in the design model is as follows,

1) Select the operation icon for the task you wish to perform from the Select or Edit toolbar

2) Select the operation icon for the object you wish to work with from the Object toolbar

Select Toolbar

The Select toolbar controls what operation you wish to perform.

Hover over the icons to display a tooltip and review the Select commands available. These are; Select, Clear Selection, Set Selection, Show All/Show Only Selection, Selection Groups, Selection Groups Filter.

Edit Toolbar

The Edit toolbar controls what operation you wish to perform.

Hover over the icons to display a tooltip and review the Edit commands available. These are; Undo, Redo, Create, Apply Attribute Set, Modify, Split/Join, Copy Attributes, Delete, Remove and Show/Alter State.

Building Objects Toolbar

The Building Objects toolbar determines which element you wish to perform on operation on:

Hover over the icons to display a tooltip and review the Object commands available. These are; Grid, Column, Beam, Truss Member, Brace, Support, Slab, Slab Overhang, Roof, Wall, Shear Wall, Shear Wall Extension, Shear Wall Opening, Truss, Portal Frame, Parapet, Dimension, Inclined Plane and Select Slab.

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Constructing the design model Columns


2.7 Columns

2.7.1 Simple Column Attribute Set

Double click on “Column Attr 1 “ from with the Attributes > Columns group on the Project pane to edit the attribute directly.

Set the title as shown below

Then select the “Design” tab.

The “Automatic Design Check Box” controls whether Fastrak Building Designer provides a section size from its analysis or if you wish to check a specific section size.

The options available in Construction Types: Simple Follows the rules for simple construction of columns General Columns with bi-axial bending, combined bending and axial and with the design

of major moments not induced by simple connections. Member Any material property used for analysis but not designed. Gable Post As general

Options for designing standard I or H shaped steel sections or Concrete Filled Hollow Sections □○ (the stiffness of

the concrete in the hollow section is not taken into account in the analysis)

Every individual structural element placed in Fastrak Building Designer can be assigned its own structural design properties. For Example

Columns: Size Constraints, Sections for Study and Imposed Load Reductions

Beams: Size Constraints, Sections for Study and Deflection criterion

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Note the information on the alignment page and leave it as it is. On this page the rotation angle and the position of the central analysis wire is set. Also structural offsets are available but these are not structurally significant.

Examine the remaining information on the remaining pages and leave the default setting – note these are the design properties that you can set in either the general or simple modules of the structural elements.

On the Size tab alter the steel grade to S275

Click “OK" and “OK” again to accept these values – you will see the name change in the project workspace window.

IMPORTANT NOTE Columns defined in Fastrak Building Designer will assume that any beam connected to the column provides a strut buckling restraint and a lateral torsional buckling restraint. If this is NOT the case then you must edit the effective lengths of the column to suit. Simple columns do not resist any lateral load, and are therefore pinned at each floor level from an analysis point of view, take care to ensure that you do not create mechanisms within your structure by using simple columns when general columns are required. You should use simple columns for the most effective design.

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2.7.2 Creating Columns

Return to the Base-2D view by clicking on the Base-2D tab at the top of the main workbook.

Select the “Create” icon from the Edit toolbar and “Column” icon from the Object toolbar

As you can see from the above toolbar the blue square around the icon indicates that the operation or object is enabled (On).

To place an individual column, click on an intersection point. To place multiple, drag a box window around the area columns are required.

In Base-2D view drag a window covering the entire grid area and let go, you will obtain the screenshot as below. You should see the following view:

Viewing the Structure in 3D

Currently all the operations that have been performed have been in the Plan-2D view. We can also model the structure in 3D, 2D elevations and Inclined Planes.

To obtain a Structure-3D view of the model, click on the “Structure” tab at the top of the main workbook.

You may need to set the view to one of the Isometric Views

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2.7.3 Deleting Columns

Switch back to the “Base-2D“ view

We need to delete columns which have been automatically placed at the node positions which are not part of the our proposed scheme.

Select the “Delete” icon from the Edit toolbar and the “Column” icon from the Object toolbar.

Now you have 2 options for deleting the columns which are not required.

You can click each column individually to delete it, or

You can left click and drag a window around a series of columns.

(Please see the diagram below for the columns which are not required)

If a multiple deletion of any structural element has been selected, Fastrak Building Designer will ask for confirmation for the deletion of these elements.

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The floor plan should look like this once completed.

You can delete any other structural element in a similar manner. By selecting the “Delete” icon from the Select toolbar and the Structural Object icon, i.e. Grid, Column, Beam, Brace etc. from the Objects toolbar.

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Constructing the design model Modifying Structural Elements


2.8 Modifying Structural Elements

Editing any Attribute Set will not alter or change any structural element placed in the model. You can change a structural element by either:

Editing the individual element, by clicking on it

Select the element or elements and amend the details shown in the Properties Window

Select the element or elements and apply an amended or new Attribute Set

Remove it from the model and recreate it using a different Attribute Set

2.8.1 Individual Structural Building Objects Properties.

Ensure that no buttons are activated in the Select and Edit toolbars

Select “Column” from the Objects toolbar

Hover over a column that you wish to edit

The column in question with turn green and the pointer icon will change and a single click will bring up the individual properties of that column.

Click on the column to Edit

Any changes or alterations made in this area are automatically saved and contained within the model. As can be seen above the Restraints tab is highlighted in red, which indicates that there is a problem in this area which requires your attention.

Click on the “Restraints” tab to see what the problem might be.

You can see the problem arises because the top of the column is currently unrestrained. This is unsurprising, because you haven’t yet placed any beams in your model.

Press the “Cancel” button and exit out of the individual properties of the column.

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2.8.2 Modification using the Properties Window

Select the “Select” icon from the Select toolbar and the “Column” icon from the Object toolbar

Click and drag a box all round the columns in the model. All selected objects will appear in blue.

Look at the “Properties Window”, you can see now that 9 columns have been selected

Change the rotation to an angle of 45 degrees and press Enter

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2.8.3 Applying an Attribute Set

Double Click on the Columns group in the Attributes folder

Edit the attribute set for “Columns”

Set the Alignment as 90 degrees

Set this as Default

Make sure that all 9 columns are still selected (shown in blue)

Select “Apply Attribute”

The following view should be displayed.

Press “Clear Selection”

It is important to clear your selections every time you use the select operation because by going to the operation of Apply Attribute Set or Delete will alter the model in the view you are in.

To ensure that all the selections sets have been cleared check the selection operation and the building objects in the structure view where the whole model is active.

IMPORANT NOTE The default setting for beams within the Fastrak attributes assumes; The top flange is fully restrained. If this is not the case please set up a relevant set of attributes or edit the specific beams. That all incoming members will provide a strut buckling and lateral torsional buckling restraint to the member. If this is not the case please edit the effective lengths appropriately.

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Constructing the design model Beams


2.9 Beams

2.9.1 Simple Beam Attribute Set

We will initially create the model using all simple beams, ensuring that the connectivity of the structure is valid and the loading on the structure will decompose correctly.

Attribute Name

General Alignment Design Type Support Size

Simple Beam Simple Gr 275 Un-

Restrained

Accept Defaults

Auto Design Ticked

Const.type Simple

Rolled Beam Simple

Connections Grade 275

Go to the attributes area in the Project pane

Expand the attributes for Beams and edit the attribute “Beam Attr 1 “

Give the Attribute Set the title “Simple Beam”

In the Design page ensure that auto design is ticked, construction type is “Simple” and that the “Gravity Only Design” is selected. Review the Design Properties and accept the defaults.

Under Alignment accept the defaults

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In the Type tab “remove” the tick in “fully restrained” and you will see a new tab appear called restraints. Let Fastrak Building Designer find the restraints positions for placed beams. So accept the defaults in this area

In the supports tab ensure that the beginning and end support conditions are set to “simple connections”

Finally under size accept that the grade of the steelwork is “S275”

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2.9.2 Creating Beams

Now that we have defined the attribute set for the simple beams we can begin to place these structural elements into the model. Beams can be placed as single entities defining the beginning and end positions or by area, defining a dragged window.

Viewing a 2D Roof Level Plan

Go to the Project pane window

Expand the “Construction Levels” under the Structure area

Double click on the level “Roof” or right click and select open a 2D view

The Initial Floor Plan you are going to be creating is shown below.

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2.9.3 Creating Beams by Area

With our grid layout set up and our column positions established we can auto generate beams between the column intersection points.

Select “Create” from the Edit toolbar and “Beam” from the Objects toolbar.

Create a window by holding down the left mouse button and dragging a box over the whole structure

The following beams will be placed.

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2.9.4 Creating Beams Singularly – Between Grid Intersections

Beams can be placed from any column intersection point or off any beam position.

Select “Create” from the Edit toolbar and “Beam” from the Object toolbar.

Click the beam start position of (B,1) then the beam end position of (B,3)

An automatic node is created on the beam where a gridline intersection coincides with a structural element.

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2.9.5 Creating Beams Singularly – Coordinated off other Beam Positions

On our original floor plan we have intermediate beams placed at third positions. We could create the remaining beams in a similar manner by placing gridlines at 3

rd positions in the bays, therefore generating the nodes and placing beams in

singularly. However, beams can be placed at any position without the need of any extra gridline to be created.

Select “Create” from the Edit toolbar and “Beam” from the Object toolbar.

Now single click on beam “SB 2/3/A-2/3/Ba”, Green nodes will appear across that beams

Use View Options to turn on beam text if necessary

Automatically the length of the selected beam is calculated and potential nodes are generated at ½ , ¼ and 1/3 points for you to select.

Select the “1/3 point node” and pull away from the node point. A connected dotted line is created.

Now select the Beam opposite “SB 2/4/A – 2/4/Ba” again the green selection nodes across that beam will appear. Along with a dotted line indicating a perpendicular node point which is automatically generated in reference to the first beam.

Click the Beam opposite “SB 2/4/A – 2/4/Ba”

Single left click of the beam SB 2/3/A-2/3/Ba Possible Green Node points

which can be selected for the start of the beam

Single left click of the beam SB 2/4/A-2/4/Ba

Note Perpendicular Node is Automatically Generated

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Select the 1/3 point generated node directly opposite. Then a simple beam will be placed at this location.

Now repeat the process to produce a beam layout as shown below.

Placing singular beams using the method above can be created in any 2D or 3D view.

When connecting to a sloping or raking member two perpendicular options are created. Either perpendicular to the first beam or perpendicular to the connecting beam.

New beam added

Automatically generated nodes readily available to be selected

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2.9.6 Copying Elements

Building Designer allows you to identify one or more elements and then copy, rotate and paste these elements to other areas of the structure as required. The copy function can be used in any 2D view or 3D view.

From the Building drop down menu select “Copy Elements”

Once the copy elements operation is activated the status bar pointer tool tip prompts you to select an element or truss and a source elements dialog box is displayed.

1) You can click a single structural element or truss (The selected object will turn green)

2) Drag a window around the elements you wish to copy. If you use the window select method you will be selecting the columns as well as the beams.

3) To deselect an element simply click on it to toggle between selected/deselected. All items selected will be highlighted green and listed in the Source elements dialog box

Select Beam “SB 2/10/3-2/9/4 “ as the screen shot below then click Next>.

Select the top of that beam along “Gridline 4 “ as the Set-out Point and click “Next>”.

Select the option of no mirroring in this instance and click “Next>”.

Assign a rotation angle of 0 and click “Next>”.

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Now the Target Dialog will be displayed. Simply click on any node point in the model that you would like to paste the Source element. In this case select the 1/3 and 2/3 points on beam SB 2/4/Ba-2/C/4 and the 2/3 point on beam SB 2/4/A-2/4/Ba. The co-ordinates will be added to the Target Co-ordinates dialog box.

If you are unhappy with any of the target co-ordinates simply highlight it in the dialog and click delete.

Finally, to create the elements in their new location click “Finish”.

Repeat for the bottom of the model such that Beam SB2/1/13-2/3/14 is copied to the 2/3 and 1/3, 2/3 points of the beams along gridline 1. You model should look as the screenshot below

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2.9.7 Create Infill Beams

Infill or secondary beams can also be created automatically by Building Designer.

From the Building drop down menu select “Create Infill Beams...”

The Create Infill Beams input screen allows us to choose; the attribute set for the beams; whether we will apply the beams to each bay in turn or to multiple bays; the method for dealing with angled beams and the spacing between them.

If you specify single bays then you simply move the cursor into the bay (a closed bay is identified in the same way it is when creating a slab), you indicate the direction of the infill beam by the edge beam your cursor is pointing to (in the example below this is the beam under the red line). Simply click to create the secondary beams in each bay.

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If you wish to apply this to multiple bays then select that option and box the area you wish to apply the infill beams to.

Then indicate the direction of the infill beam by selecting the appropriate edge beam and click to create the beams.

The number of infill beams is either calculated automatically to fit a specified number or by manually entering the distances along the supporting members. For example, if you specify, number = 2, then your beams will be placed at third points. If you specify a spacing of 1m,2m,3m,3m it will simply apply as many beams as will fit in the bay at the specified spacing.

Using the attribute set Simple Beam and an infill number of 2 beams (i.e. equally spaced at third points) ensure that all four of the main bays in your model are filled in.

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Close the infill beams dialogue once complete.

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2.9.8 Creating Beams at Absolute Distances

Additional Beam Layout I

Create the additional Beams in Area 1 using the “½ point node“ and perpendicular points

When defining the geometry of the building the automatically generated nodes may not be appropriate in defining the beams start or end position.

In Fastrak Building designer an absolute or unique ratio distance can be placed, in relation to the length of the beam.

When a start or end position is defined and the standard green nodes appear on the beam, press any numerical value on the keyboard. A pop up dialog box will appear.

1

2

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This dialog box allows a ratio or an absolute distance to be entered. This value is dependant on the direction the beam has been drawn in and will be measured in the direction of the element arrow on the beam. A reversed command is added to measure from the other side.

Placing beams singularly can be a tedious task Fastrak Building Design allows the user to copy and duplicate single or multiple elements to other parts of the model.

Additional Beam Layout II

Select “Create” from the Edit toolbar and “Beam” from the Object toolbar

Now select the beam that runs from “A/1 – A/3”, from which the new beam will start.

Instead of selecting a predefined node press any number on your keypad. A pop up box will appear.

Enter the value of “3m“ then press OK

Then select the beam across from that one and a perpendicular node will be created, establishing a horizontal beam.

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Create the other beam that start 5m from A/1

Return to the Structure-3D view to see what has been modelled so far.

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Constructing the design model Grouping


2.10 Grouping

The Selection Group Pane helps to keep your model organised and allows you to edit large numbers of elements quickly and

easily. It is used in conjunction with the ”Selection Groups” , “Selection Group Filter” and “Show/Alter State” icons which can be found on the Select and Edit toolbars.

The first time you use an attribute set to create new members a new group is added to the Grouping tab with the same title as the attribute set, any further members created using this attribute set will also be added to this group. Compare the attribute sets with the Grouping tab and the link between the two becomes evident.

The automatically created groups are not fixed however; new groups and sub-groups can be created and existing groups can be edited to suit your needs.

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The groups can be used in conjunction with the properties window to select and edit large numbers of elements at once, allowing swift rationalisation of a model.

NB The attribute set used to create the elements only dictates the initial group name and assigns new members to that

group. If you use an attribute set along with the ”Apply Attribute” tool to alter the properties of an existing member it will not re-assign the member to the corresponding group; the existing member will be left in its original group and it is up to you to alter the group it belongs to.

2.10.1 Creating Groups and Sub-groups

Select the Groups tab in the workspace window

Right-click over the Simple Beam group and choose Create Sub-Group

Expand the parent group to see the sub group, select this sub group and then left-click to rename; we will call this first sub-group Edge Beams

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Select the Roof-2D view and select the edge beams (including the trimming steel) as shown below

Right-click over one of the members and choose “Add Selection to Selection Group”

Select Existing Group and then choose Edge Beams

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Return to the Edge Beams folder in the Grouping tab to view the changes

Alternatively you can simply select the members you wish to group together and create a new group or sub-group from the Selection Group menu

Select the primary members as shown below

Right-click over one of the selected members and choose Add Selection to Selection Group

Select New Group and name it Primary Beams; set the parent folder to Simple Beam.

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Select the secondary members as shown below

Right-click over one of the selected members and choose Add Selection to Selection Group

Select New Group and name it Secondary Beams; set the parent folder to Simple Beam.

Go to the Grouping tab to review the changes

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Elements, Groups and Sub-groups can also be re-organised by dragging and dropping them in the Grouping tab (use Shift + Arrow up key to select multiple items)

NB Any new beams you create using the Simple Beam attribute set will be added to the parent group. To add beams into the newly created sub-groups you have the choice of either editing the elements afterwards OR copying the attribute set and re-naming it to match the sub-group you wish to add to (Edge Beams for example)

It is also possible to use Selection Groups in conjunction with Show/Alter State to place elements in different pre-defined groups. Simply select the Group Name to display and click on any beam to add to that group.

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2.10.2 Using Groups to Edit Properties

Toggle on both the “Select” and “Selection Groups” icons from the Select menu

Hover over any member and all the members in its group will be highlighted

Select a group by clicking on one of its members and the Properties window will display the group’s editable properties.

Edit any of the properties and the changes will be applied to the group as a whole

2.10.3 Selection Group Filter

To aid group selection there is a selection group filter that will switch groups off in the main window; this can be particularly useful in larger models

Toggle on the “Selection Group Filter” , the View Selection Groups window will be displayed.

Check or un-check the tick boxes alongside each group to toggle the groups on/off in the main view

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Constructing the design model Copy Elements


2.11 Copy Elements

As the building comprises two similar ‘wings’ we are going to copy all column and beam elements in the model and rotate 45 degrees.

Select “Copy Elements” from the Building menu.

Select every single element except the column on grid line “A/4”. This is simply achieved by dragging a window around the structure and then de-selecting the column on A/4. When all Source elements are selected click “Next>”.

Note. You may need to review the Object toolbar and ensure no object icon is selected. This allows you to select all elements. If the column icon is depressed this allows you to only select column objects.

In the Set-out Point dialog select the top of column A/4 (the dialog will automatically move to the next one).

Mirroring - set as “no mirroring” and click “Next>”.

Rotation dialog - Now set the Rotation Angle to “45 degrees” and click “Next>”.

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In the Target Coordinates dialog place the source elements at the grid reference C/4 of the roof level by left clicking

over the node. Review the information in the Target Coordinates dialog. You can edit directly if needed.

The model should now look as below

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Grid line 2 is not copied across as no source elements existed on that gridline.

The orientation of the columns has been adjusted to suit the new orientation in the model.

N.B. Copied elements remain in the same groups as their source elements

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Constructing the design model More Grids, Columns and Beams


2.12 More Grids, Columns and Beams

The arrangement of the ‘interface area’ is shown in below.

2.12.1 Sharing and Modifying Gridlines

The new gridlines created using Copy Elements will not be Shared Gridlines.

Return the Base-2D view.

Click on “Select” and “Grid”

Drag a window round the entire model to select all the gridlines

Select Shared = Yes in the Properties Window

Clear the Selection

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The interface area requires the construction of 3 gridlines as shown below

Create a gridline “1.5m“ in the original area using the “Parallel Grid” icon on the Grids toolbar

Create 2 new grid lines @ “1m“ and “1.5m“ in the new area.

Note it is possible to create multiple gridlines by typing the running dimension values into the dialog as shown below and clicking create

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Use “Modify” and “Grid” to extend the three gridlines as shown above as an extension

Click on the Gridline, the white ‘grip point’ boxes should appear

Click on the end grip point

Click again where you would like the extended gridline to end

To ensure that the gridline is extended in a straight line, make sure that the information tip shows “Extension – Length” and not “Coord”

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2.12.2 Creating More Columns

Now place 2 columns at an angle of 22.5 degrees rotation in the new interface area. Use the intersection points created from the modified gridlines. Possible methods are listed below.

Set attribute and Apply (click drag or individually click)

Individually into every column having nothing selected

Selection tool and select the columns in question and use he properties window

Set attribute, and then select the columns in question and apply defaulted attribute

Also apply a rotation to the column at “C4” and along the intersection line at a rotation of “22.5 degrees”

2.12.3 Creating More Beams

Create the floor plan layout as shown below using the techniques described earlier in the training course.

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Constructing the design model Slabs


2.13 Slabs

Although all the beams are currently non-composite we will specify a composite slab for use later on the model development.

2.13.1 Composite Slab Attribute Set

Richard Lees Composite Profile Metal Decking (Ribdeck AL)

Slab Depth = 150mm, Concrete Grade = 30,

Reinforcement (slab) = Mesh A142 throughout, Mesh Type A, Yield Stress @ 460N/mm^2

Decking = RLSD AL, Gauge = 0.9mm

Standard Stud Layout, Stud Height = 100 mm

“e” distance information = 50mm (to be used when we design composite beams)

Create a new Slab Attribute Set

Set the attribute title as shown below

Click on the Position tab and leave the orientation to 0 degrees.

Click on the Floor Construction Tab and set the slab depth to 150mm and set the concrete grade to C30.

Important Note When creating load cases, you can opt to calculate the self wt. of the slab automatically. If you select this option it is critical that you select the correct material attributes. Do not forget to allow for ponding when appropriate.

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Under the Profile decking tab set RLSD as the manufacturer using “Ribdeck AL @ 0.9 gauge”

Then click on the reinforcement option and you will notice that the slab reinforcement option is referred to as the “Other reinforcement”

Reinforcement (slab) = “Mesh A142” throughout, Mesh Type A, Yield Stress @ “500N/mm^2”

Then Press “OK” to establish the attribute in the workspace window.

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2.13.2 Creating Slabs - by Group

Slabs can be grouped together in the model such that the same properties and orientation are retained in a group. Thus for any change in orientation or change in slab properties a new slab group is required. In our construction model we will be creating 3 different types of slab groupings to relate to a different slab direction.

The default attribute is only taken when new slab is displayed in the drop down box. If an existing slab group is selected then all the properties including orientation have already been defined and the slab is created based on those.

Return to the “Roof-2D “ view

Use “View Options” to turn off the – beam names, axis names, gridline and dimensions

Turn on “Slab Name”

Select the “Create” and the “Slabs” icon. You should also note a slab drop down list with the Slab named “New Slab”.

Hover your mouse button into an individual bay and you will see that the exterior bounded area will become highlighted by a green line.

Place a single slab in the upper North West corner of the building as shown

As you will see the slab will be place as a grey colour in the bounded area. This shows good connectivity in this area and shows that all the beams are connected in the structure.

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An example of bad connectivity where the slab will extend beyond the initial bay

Note that the Slab grouping tool bar has now changed to the title “Slab 1”

Slabs can be placed using a click drag method as with beams.

Perform the action as shown below and place multiple slabs in the selected area.

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Note that the slab placed originally in the upper North West corner is a slightly darker colour than the rest of the slabs.

Since we have an overlapping of slabs in this area we need to delete one of the slabs.

Have “Delete” and “Slabs” selected from the Edit and Object toolbar.

Hover your mouse pointer over the bay in question, the whole bay will be highlighted in green, and perform a single click

Exit out of the Delete operation and you will notice that the colouring of the slabs is now consistent.

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2.13.3 Changing Slab Orientations

The slabs placed all have a zero degree orientation. What happens when we want to change an individual slabs properties say to an angle of 45 degrees?

From the Select and Edit toolbar have nothing selected and from the Objects toolbar just have “Slabs” selected.

Select an individual bay which will become highlighted in green and left click to enter the properties.

Enter a rotational value of “45 degrees”.

Click OK

Even though only one individual bay was selected all the slabs have rotated to an angle of 45 degrees, because they are all grouped together as “slab 1”.

Change the orientation back to “0 degrees”

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2.13.4 Adding New Slab Groups

Select “Create” on the Edit toolbar an “Slabs” on the Objects toolbar. Extend the slab group drop list and select “New Slab”

The default attribute will now be used to define the properties for the slab group 2

Now place a slab in any area in the right hand side of the building.

Change the orientation for “Slab 2 to 45 degrees”. Slab 2 will change but all the Slab 1 slabs will stay at 0 degrees.

2.13.5 Final Slab Floor Plan

Using the techniques described above create the slab floor slab arrangement as shown below.

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Constructing the design model Validating the Structure


2.14 Validating the Structure

Validation is a pre-check before design. It checks the connectivity of the structure, decomposition of the structure; check the design definition of the structure and the structural objects properties. Basically a pre-check before the design phase, so that the model should hopefully complete the design process.

2.14.1 Staged Modelling and Design

Our piece of advice when you are modelling in Building Designer is DO NOT BUILD THE ENTIRE MODEL BEFORE YOU VALIDATE AND DESIGN IT. It is important that you build the model, validate and design it in a staged process, for example:

Validate and design ONE floor before copying it up the building,

Resolve the gravity design before looking at the lateral design,

Resolve the sway stability before applying the wind loading. There are often many nuances to creating your model, in particular with composite design, and it is much more effective to resolve any issues once (before you copy the floor to other levels in your model) than it is to copy the floor to (say) ten other floor levels, and then address the (usually simple) issues on each copied floor (in this case ten times the work!).

2.14.2 Validating

Press the “Validate” button and the “Output window” will display information.

The validation process relates information back to the user using the output window. Therefore it will appear every time the validation button is pressed.

These results can be filtered out into Design (everything), Report, Errors and Warnings using the tabs along the bottom of the dialog.

As you can see there are three errors relating to unsupported elements.

2.14.3 Element Reference Names

The next number usually determines the floor level number at the start of the beam. In our case floor 2 which indicates the second level in the model; Base=1, Roof=2.

The next 2 reference numbers indicate the intersection of gridlines which establish the beginning of the member.

SB = Simple Beam GB = General Beam CB = Composite Beam

SC = Simple Column GSC = General Column GM = General Member

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Constructing the design model Validating the Structure


2.14.4 Finding Elements with Validation Issues

In the “Output” window double click the reference name of the beams in question in turn.

The beam in question will be highlighted blue and indicated by an arrow.

Notice the element direction of the indicated beam and the gridline references that establish the location of this particular beam.

Change to the “Structure-3D“ view.

Access the “View Options” dialog box and turn off the “Slabs” and the “Slab span directions”, to simplify the view.

“Validate” the model again

In the “Output” window double click the reference name of the beams in question in turn.

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Constructing the design model General Beam & Columns


2.15 General Beam & Columns

2.15.1 Cantilever General Beam

All the beams in this model are simple beams with end connections of just simple connections (shear only).

This cantilever area will cause a degree of freedom in the z direction (vertically) due to no fixity or no stiffness at this position.

We will change the short beam connected to the column to be the supporting beam and make it a General Beam cantilever.

Design Element Cantilever Beam

Design Method Adopted General

Support Conditions Fully Fixed and Free

LTB Top Flange Restraints Non Cont Top Flange Restraint

The connecting beams framing into the cantilever can stay as Simple Beams.

2.15.2 Modifying Beam Properties

Ensure that no icons are active on the Select or Edit toolbar. Select “Beam” from the Object toolbar.

Click the beam you intend to be a cantilever to view its properties.

Change the Construction Type to “General”

Notice when the construction type has changed to general, extra options appears for LTB restraints and Strut Restraints.

Click on the “Supports Tab”

The supports must accurately reflect the end conditions in which the beam has been placed into the model.

Take note of the pink element direction arrow which signifies position 1, beginning of the member and position 2 the end of the member.

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Set the support at the column end as “Fully Fixed” and the other end as Free.

Click on the “Restraints (LTB)“ and uncheck the continuous top flange restraint.

View the design options under “Strut Buckling”

Fastrak Building Designer will always assume an effective length in Strut and LTB buckling of 1.000L in all situations.

Press “OK” to confirm the changes to the cantilever beam.

Note the member reference has changed from SB (Simple Beam) to GB (General Beam)

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2.15.3 Simple Columns

The model up until the creation of the cantilever beam had been simple in nature with beams and columns being pinned at either end.

The simple beams will induce eccentricity moments in the design of the simple columns. As defined in BS5950: 2000 clause 2.1.2.2 Simple Design.

The moments induced will not adversely effect other any part of the structure

The flexibility in the connections may result in non-elastic deformation of the structure other than the bolts.

The structure should be restrained laterally, in both in-plane and out-of-plane directions, to provide sway stability

2.15.4 General Columns

By creating the cantilever general beam we are acknowledging that the loading, end conditions or supports are not adhering to the BS5950: 2000 clause 2.1.2.2 Simple Design

By specifying a cantilever, the resulting true moment developed by the cantilever could adversely affect the supporting simple column.

As an engineering decision we will change the supporting Simple column to General.

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2.15.5 Modifying Column Properties

Ensure that no Edit toolbar commands are active, select “Column” on the Building Objects toolbar.

Click the column you intend to be a General to view its properties.

Change the Construction Type to “General”

“Validate” the model again.

The “Output Window” should read as follows.

All the beams in the cantilever area are now supported. We now have 1 Error and 2 Warnings to consider.

While we are unable to proceed to design until all errors are resolved. Warnings are simply warnings for you as the engineer to consider. This could simply be an assumption that we have made on your behalf that we are flagging to your attention. You can ignore these warnings if you understand the significance of them.

The warning related to the load combinations above should be obvious, the warning related to the ‘moment frame’ setting for a column simply affects the initial sizing routines which are different for moment columns to axial only columns.

Since no loading has yet been placed on to the structure we can ignore the error message of “At least one active critical strength gravity combination has to be defined” and the remaining warnings.

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Constructing the design model Simple Columns with Cantilever Simple Beams


This section is for information only

2.16 Simple Columns with Cantilever Simple Beams

Fastrak Building Designer allows the use of simple cantilever beams on supporting simple columns.

The design for the beam and column is likely to result in warnings, most probably due to forces which are not normally checked in simple construction design, but the design may remain potentially valid. This is an engineering decision which is required by you whether to leave the structural elements, simple in their construction.

The following procedure shows how simple beams can be set as cantilevers.

2.16.1 Simple Beam Cantilever

1) Leave the Construction Type as Simple

2) Set the support options as Fully Fixed and Free, depending on the direction of the element.

3) Uncheck the option of Fully Restrained. An extra tab will appear called Restraints. In the restraints dialog box the effective length of the cantilever can be changed.

For a simple cantilever, Fastrak Building Designer will assume an effective length of 3L. This can be changed, individually for the beam in question.

2.16.2 Simple Column Restraints

For Simple Columns Fastrak Building Designer will always specify an effective length of 1L between the points of restraints. This is true for Strut and LTB restraints.

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Load cases and combination Simple Columns with Cantilever Simple Beams


3.0 Load cases and combination

Creation of load, load cases and combination

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Load cases and combination Load Cases


3.1 Load Cases

3.1.1 Loading Toolbars

The Loading and Loads toolbars are located at the bottom of the screen.

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These toolbars works in conjunction with the “Create” or “Delete” options on the Edit toolbar

3.1.2 Load Types

Slab Loads

All loading below will be initially decomposed by the slab and then on to the structural members

Floor Loading Any location on that floor level where a slab exists load is placed

Area Loading An individual slab area bounded by steelwork

Point Loading Can be placed at any location on the slab

Line Loading Can be placed at any location on the slab

Patch Loading A rectilinear patch can be placed at any location on the slab

Variable Patch Can be placed at any location on a slab or roof; ideal for modelling snow loads.

Element Loads

All loading below are placed directly on the structural members

Nodal Loading Nodal loads can be placed at any column position or beam & column intersection point

Element Loading UDLs, VDLs, Point, Moment and Trapezoidal loads, can be placed in the local x, y, z and global z directions

Wind Loading Nodal lateral loads can be placed as wind loads in the intersection of beam column elements.

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3.1.3 Tutorial Model Load Cases

We will load the structure as if it’s going to be designed as composite, even though the beams at this moment in time are all non-composite.

Steel Self Weight = Automatically calculated

Slab Wet (slab dead load in the construction stage) = 3.0 kN/m2

Slab Dry (slab dead load in the final stage) = 2.5 kN/m2

Construction Live = 1.0 kN/m2

Imposed = 2.5 + 1.0 = 3.5 kN/m2

Various Dead Loading = example loads including 8 kN/m perimeter loading

All individual loading placed in a loadcase can be created graphically.

When designing structures with composite beams you must ensure that you create both a Slab Wet and a Slab Dry loadcase (as above).

3.1.4 Creating Load Cases

Press the “Edit Loadcases” icon on the “Loading” toolbar or select the Loadcases option from the Loading drop down menu.

The following loadcases dialog screen will appear.

Click on the “Add” button.

Enter a loadcase title

Define this loadcase type from the drop down list

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Check the “Include in Generated Combinations” if you would like the Combination Generator to include the loadcase in the generated combinations.

For our loadcases ensure Construction Live is unchecked – all others can be checked.

The Slab Wet and the Slab Dry loadcases must be defined by the user if composite beams are to be designed. When selecting Slab Wet and Slab Dry Load cases you will have the option to allow the software to automatically calculate the self wt. of the slab.

If you are using a composite slab with a profile metal decking this option will calculate the self wt. of the concrete slab and steel decking based on the properties set up in the slab attributes. You may still choose to enter your own floor load. If you wish to do this please do not forget to allow for the effects of ponding.

Add the “Various Load Cases” and press OK

To place loading in a particular loadcase we will to select the loadcase and create the required loading graphically in the 2d or 3d views as appropriate.

IMPORTANT NOTE Due to the automated nature of the design process it is absolutely critical that the correct loading is input. Effective composite design requires a design of the construction (wet slab case) as well as the final Dead + Super condition. If you wish an imposed load to be reduced based on the number of floors, then this must be selected when the relevant imposed load case is created.

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3.1.5 Creating a Floor Load

Pick the “Slab Wet” load case from the drop down list on the Loading toolbar.

Click “Create” then “Floor Load”

If Floor Loading is not available, check View Options and/or Edit Loadcase to ensure that automatic loading is unchecked for this exercise.

Click on any single slab on the model. A dialog box will appear.

Enter the value of “3.0 kN/m2”.

The extent of the applied load will be shown in green across the floor.

Change the loadcases in the drop down list and complete the rest of the Floor Loads.

Slab Dry 2.5 kN/m2

Construction Live 1.0 kN/m2

Imposed 3.5 kN/m2

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Viewing Loading in the 3D-Structure View

Return to the 3D-Structure view.

Turn on all the Loading Types and Load Value in View Options. Note if your slabs are turned off the load cannot be displayed.

Select a load case from the drop down list.

Select the “Various Dead Load” loadcase.

Create your own examples of the following slab and element loads.

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3.1.6 Creating Other Slab Loads

Area Load

An area load is contained to an individual bay bound by beams.

Point Load

Point loads can be placed at any position on a slab. Initially a reference point has to be defined and the position of the point load approximated. You can then modify the offsets from the setting out point to accurately define the load value and position.

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Line Load

Line loads can be placed at any position on a slab. Again a reference point has to be defined then the start and end points of the line approximated. A dialog then allows the value to be input and the offset dimensions to be confirmed/modified.

Patch Load

A rectangular patch can be placed at any position or angle on the slab and does not have to be confined to the surrounding steelwork. Again define an insertion node point then the start and end points of a rectangular patch. Finally a rotation angle and then firm up the values in the dialog box displayed.

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Variable Patch Load

A varying patch load can be placed at any position or angle on the slab. Define the insertion node, boundaries and rotation angle of the load as above. This time there are additional inputs required for the load values at the opposing edges of the patch.

Note that the load can only vary in one direction (not two) and hence the input will force you to align certain values in order to achieve this.

3.1.7 Creating Element Loads

Element and nodal loads can be placed on the structural element wire itself or at any node point.

Nodal Load

Nodal loads can be created at intersection points and at column positions. No reference point is required

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Element Load

Individual structural elements can be loaded in a various directions and loading types.

Perimeter Loading

Full UDL Element Loads can be placed on the centre line of all the perimeter beams on the current floor quickly and easily using the Create Perimeter Load option.

Select the “Roof-2D view” and the “Various Dead Loading” loadcase.

Select “Create Perimeter Load” from the “Loading” menu.

Enter “8.0 kN/m” for the perimeter loading.

All the perimeter loadings will be seen as element loads around the perimeter.

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3.1.8 Modifying Loads

Ensure all operations on the Select and Edit toolbars are inactive.

Select the appropriate Load Type on the Loads toolbar

Then click over the load you wish to modify in the model

Adjust the value in the dialog.

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3.1.9 Deleting Loads

Any loading placed on a structural model can be deleted graphically. Ensure Delete is selected on the Edit toolbar along with the type of load you wish to remove on the Loads toolbar.

Then move your mouse pointer over the load and it will become highlighted.

Single click over the load to remove it from the model.

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Load cases and combination Load Combinations


3.2 Load Combinations

3.2.1 Defining Combinations

Press the “Edit Combinations” icon on the Loading toolbar, or select Combinations from the Loading menu.

The Combinations dialog screen will be displayed

In this dialog box combinations can be added or edited.

If you have composite beam you must create a construction stage combination using the ‘Add Constr.’ button.

You must create at least one combination which is a gravity combination (this becomes two if one of them is the construction stage combination).

You must create at least one ‘critical’ gravity combinations.

A critical combination is one which the sections will be designed for, you must have a least one gravity combinations (usually a Dead + Live combination) and you may have up to four critical Lateral load combinations (usually the four principal NHF directions or the 4 principal wind load directions). All other combinations will be check, but will not form part of the auto design process.

The generate button will automatically generate a range of load combinations for the current set of load cases, while this can be very useful, it should not be used without an understanding of the process.

For this example we will stay with the manual creation of load combinations

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Click the “Add” button.

On the left hand side you will see a list of available loadcases, and on the right hand side the loadcases that have been included in the combination. The arrow is used to move the highlighted loadcase from one side to the other.

Highlight the “Imposed and the Various Dead” loadcases by single clicking on it and use the arrow to the right to include this loadcase.

The load factors for the individual loadcases are automatically created. There are separate factors for strength and serviceability. These load factors can be altered by double clicking in the Factor box.

Press “OK” and click on the “Add Const.” button to create a new design combination.

Create a construction stage combination titled “Construction Stage”

Include the “Self Weight, Slab Wet, and Construction Live” loadcases

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Fastrak Building Designer will automatically define and apply NHF’s (Notional horizontal forces) in the global directions of X+, X-, Y+ and Y- to account for “lack of fit” and can be included in any ULS Combination with a class defined as “Lateral”.

NHF’s will be discussed in a later exercise.

“Validate” the model

The following output message should be created.

As you can see a warning is displayed indicating that no NHF’s forces have been included in the model but the structure is now valid and a design can now be performed (indicated by the active design button next to validation).

IMPORTANT NOTE The Gravity and Lateral settings are important. Members such as simple beams, composite beams and simple columns can be set as ‘gravity only’. It is the default setting for simple and composite beams. Members set in this way will ONLY be designed for the gravity load combinations. This is important as it will significantly speed the design process and help create better output for those beams which are only subject to gravity loading. Most simple and composite beams, by definition of being pinned are not affected by lateral loading. If as a result of being a transfer beam, it will be affected by lateral loading it is important that the beam attributes are edited and the gravity only design attribute is switched off.

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Performing a gravity design Load Combinations


4.0 Performing a gravity design

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Performing a gravity design Design Options


4.1 Design Options

Fastrak Building Designer uses an iterative process in the design of all its structural elements. We can control the design criteria by setting some design options prior to analysis.

Under the “Design” drop down menu select “Design Options”

Once selected the following dialog screen is displayed.

Within this dialog and the associated tabs – Design Control, Force Limits (Members and Connections), Design Codes, Element and Portal Pre-sizing, Composite – we can control the design process as discussed below.

4.1.1 Design Control

Once a design has been undertaken and the model is in check mode we can specify which elements on a level by level basis or sloped/vertical basis are check designed thus speeding up any subsequent design check passes.

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Performing a gravity design Design Options


4.1.2 Force limits - Members

FTBD undertakes an analysis on the entire model and thus an iterative process is required.

The design forces are a result of the analysis and come about as a result of the distribution of stiffness in the model, frame action, displacement and arrangement of steelwork.

The individual design elements within FTBD are specifically set up to design for particular forces as detailed below.

Simple Beams – pin ended only, designed for shear and uni-axial major axis bending.

Composite Beams – as above but composite design with profiled metal decking or PC units.

General Beams – Any end fixity, designed for shear, bi-axial bending (major and minor axis under any load direction) and axial force.

Simple Column – Follows the rules for simple multi storey columns defined under cl. 4.7.7

General Column – For columns which are outside the scope of simple column design (the design process is then for a general beam/column but with the allowance of eccentricity moments when applicable.

The user must choose the appropriate member types to suit the most effective design process. Simple and composite beams, and simple columns are specifically set up to consider only certain types of loading and hence mimic a simple ‘hand design’ of a simple multi storey structure. Where appropriate the use of simple construction and the associated design elements is likely to yield the most efficient design.

The user can set force limits within this dialog for the construction types that they consider they are happy to ignore. For example the analysis reports back an axial force on a simple beam of 2kN. With a user specified axial force limit set at 5kN the simple beam is designed ignoring the analysis force and a pass or fail status is reported for the element based on the shear and uni-axial checks. With the user specified value set at 1kN the simple beam is again designed based on shear and uni-axial checks but, because the user specified axial force limit is less than the analysis force a warning is reported against the element advising you of this.

In the Design Options set the values and options as shown below and press OK

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Performing a gravity design Analysis Options


4.2 Analysis Options

Under the “Design” drop down menu and select “Analysis Options”

4.2.1 Analysis

First Order Elastic Analysis

This analysis type is suitable when λcr is greater than 10 and the second order effects are small enough to ignore, and should always be used for initial design.

Second Order Analysis – BS 5950 – Kamp approach -

This analysis type is suitable when λcr is between 4 and 10 i.e. the structure is sway sensitive.

This method is the preferred second order analysis approach as this uses a simple amplification of the first order analysis forces as per BS 5950.

Second Order Analysis – two step iterative approach -

This analysis type is suitable when λcr is between 2 and 4 or for specific building type which might fall outside of the effective use of the Kamp approach. This includes some portal frames. For detailed guidance please see BS 5950.

As per SCI P 292 no structure should have a λcr less than 2.

This method is a ‘true’ second order method, but should be used with caution. As with all ‘true’ second order approaches it will only provide an analysis for a structure that does not ‘collapse’ under the design loading. Hence great care must be taken when using this approach to have a stable model.

For a typical floor to floor building this method gives no better answers than the much simpler Kamp approach.

When a Second Order Analysis option is selected, NHF’s are automatically switched on and the include sway stability analysis is performed. Further options are available for the calculations of the “Amplification Factor – Kamp” to be used in the analysis

For more detailed Information on the way that Fastrak Building Designer Handles Sway, please refer to the CSC Advisory Note “Building Designer Sway Advisory Note”

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Performing a gravity design Performing a Design and Design Results


4.3 Performing a Design and Design Results

There are three design options.

If you hover over the icon you will be provided with the relevant ‘tool tip’ that will tell you what the icon does. Perform Gravity sizing

This will analyse only the gravity load combination and design all relevant members for the gravity loading.

You must complete a gravity sizing before you can proceed to a lateral sizing or a full design. Perform Lateral sizing

This will analyse up to four lateral load combinations and design the relevant members.

Performing a lateral sizing is optional and will not be required for all structures. Perform Full design (check)

This will analyse all load cases and combination, and check all relevant members (note that gravity only members will still only be checked for gravity load combinations).

“Validate” the model.

Press the “Perform Gravity Sizing” icon

The design will proceed, and you will see a Design Progress dialog indicating its progress.

4.3.1 Workspace Window

On completion of the design the Workspace window will automatically switch to the workspace results tab, which shows the results of the structure graphically.

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Performing a gravity design Show / Alter State Options


The two critical issues are the max nodal deflections and the check of the loading summary which shows load in versus load out of the structure. Before checking anything else you should first check these two. Max Nodal Deflections. This shows the maximum deflection of the analysis model under any of the load cases/combinations. It is intended to establish if the analysis model is valid. If any node on the model deflects more than 1 m then an orange ‘warning’ triangle will be shown indicating that the analysis model is ineffective and any other results should be treat with caution, Other than for the sway stability check, the design procedure does NOT apply deflection limits to the lateral design. You should ensure the performance of your structure in lateral deflection by checking the 3D deflection diagrams as appropriate. Loading Status The loading status shows the loading applied to the model in X,Y and Z and the loading at the foundations for the same load case. If these values do not match exactly then the software will flag a warning by marking the load case with a red X.

4.4 Show / Alter State Options

The ‘show/alter’ state function allows rapid graphical visualisation and modification of a wide range of basic model functions. The icon shown on the select toolbar will activate show/alter state. There a four main windows as shown below. Outlined below are some of the main functions that the show/alter state may be used for.

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4.4.1 Design Status

This is the default show/alter state view after a design has been completed. The elements of the model will be coloured to represent the key shown in the dialog below. Alternatively you may select the design utilisation option which will show by colour code the maximum utilisation of the members.

4.4.2 Moment Releases

The FE stiffness model can be graphically visualised in this mode, along with the end fixity of the elements contained in the model.

General Beams, General Columns, General Members and Trusses may have the end fixity adjusted in this way.

As can be seen from the illustration above, the Building Objects toolbar is used to display the element type end nodes

The node or nodes of interest are then clicked on to select them and the Properties window is then used to adjust the fixity as required

The Clear selection icon is used to clear the previous selection.

This approach can be used across a whole range of options using the show/alter state function.

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4.4.3 Alter Diaphragm

In the building levels you may activate the diaphragm modelling on a floor as ‘no diaphragm’, ‘single diaphragm’ or ‘slab items defined’. Whilst the use of diaphragm modelling can be an invaluable tool, the incorrect use of diaphragm modelling will almost certainly give inappropriate results. As such these modelling tools should be used with care. If you are unaware of the impact of using diaphragm modelling you should seek guidance.

Any diaphragm will, by default, constrain the nodes such that they are all linked by the action of the diaphragm. Thus lateral forces are assumed to go directly into the diaphragm. It is possible via the show/alter state function to release the nodes of a certain element such that its in-plane forces will result in the element. Further it is possible to create separate ‘unconnected diaphragms’ even if the slab exists – see below.

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4.4.4 Show Diaphragm

The screenshot below shows two diaphragms on a single floor level defined by slab items

4.4.5 Wall Surface

A wall panel has an internal and an external face (in order for the Fastrak Wind Modeller module to correctly define the Cpi and Cpe values). In addition, the Simple Wind Loading tool applies area load to an external wall panel face only. The show alter/state allows you to defined the ‘correct; surface face. Clicking on an individual wall panel in the model toggles the face as being internal or external. You should rotate around your model and ensure that the wall faces are consistent. Roof Type This show alter state view is relevant for use with the Fastrak Wind Modeller module (discussed further in the Day 2 course). The show/alter state allows you to select from the colour key the type of roof panel you wish to define. The program will then determine the coefficients from the appropriate table in BS6399.

4.4.6 Report Level

The Individual structural elements design report options can be controlled graphically via this show alter state view. The default level of output will be a single line summary showing a pass/fail status and if appropriate the critical utilisation level. Using the report level setting in the show alter/state you can select an increased level of output for a number of critical sections. Take care not to select too many members or too greater levels of output.

4.4.7 Integration Status

The show/alter state integration status can provide a visual status of your model when linking to 3D+ and Revit Structure. This view provides details about which elements in the model have been modified (and thus design data changes have occurred) by the external application. Further information about the link is provided in a separate training course relevant to either 3D+ or Revit Structure as appropriate.

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Lateral movement under gravity loading Show / Alter State Options


5.0 Lateral movement under gravity loading

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Lateral movement under gravity loading Validity of the Gravity Design Results


5.1 Validity of the Gravity Design Results

When the design for the structure has completed, the Workspace window automatically changes to the results tree.

Adjust the windows of the screen as shown below for a clearer view of the results tree.

5.1.1 Maximum Nodal Deflections

The maximum nodal deflections are identified and reported back in the principle axes. These values are taken from the loading established in the model. Clearly if these nodal deflections are too high there may be a mechanism developing or with the structure as it stands not being capable in handling the forces applied to it.

If large amounts of deflections are reported, the analysis results used in the design of the individual elements may be suspect, and may be incorrect. The global deflections of the structure need investigating before any time is taken looking at the design of individual elements.

Have a look at the Maximum Nodal Deflections for the model and determine the validity for the design of the structure.

As can be seen from the results obtained for our structure show significant lateral movement.

Results obtained for your model may be slightly different due to different loading.

Clearly with such huge lateral deflections of our structure in X, and Y the analysis results obtained for this structure in the design of the individual elements may be suspect.

The structure modelled for gravity design in an elastic analysis, is susceptible to lateral movement.

This excessive lateral movement should be eliminated before the design of any structural element is accepted.

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Lateral movement under gravity loading Resistance of Lateral Movement


5.2 Resistance of Lateral Movement

5.2.1 Methods Used to Resist Lateral Movement.

1) Diaphragms

2) Steel Bracing

3) Rigid Bays

4) Shear and Core Walls

5.2.2 Diaphragm Action of Floors

A “diaphragm” constraint has significant implications to the analysis and structural model. It is important that the diaphragm constraint is only applied where it actually applies in reality. Two types of diaphragms can be defined in Building Designer:

Single Diaphragm

When a single diaphragm is applied to a horizontal floor, then all ‘nodes’ in the analysis model in that plane will be included in the diaphragm. This means that every node in that plane is constrained to move in such a way that the distance between the nodes is maintained as a constant. Since the distance between any two nodes in the plane is constant, no axial forces can develop in any member that lies in the plane of a diaphragm. Some of the effects that this generates (which some engineers may sometimes regard as “unwanted”) are noted below

No axial loads found in members which lie in the level of a diaphragm

Example; Plan Roof Bracing

Applying diagram action at intermediate floor levels will restrain this level within the whole structure.

Example; Single beam modelled at an intermediate stringer level.

Structural Element Supports located in the level of the diaphragm

Example; the supports may attract forces induced by the diaphragm action of the floor.

Separate floor areas tied together by a discrete diaphragm

Example; two separate structural floor layouts acting as one with diaphragm action

Slab Items Defined

“Slab items defined” allows separate floor areas on a horizontal floor level to be defined as separate Diaphragms thus alleviating issue 4) above. This can be extremely useful where for example you have a part floor part roof level or a large central void in the model.

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Lateral movement under gravity loading Applying Diaphragm Action to a Floor


5.3 Applying Diaphragm Action to a Floor

Select “Levels” from the “Building” menu

Tick the option to define the Roof level as a “Floor” and check the “Single diaphragm” option.

Accept the imposed load reduction re-calculation. Clearly with a single floor level the reduction will make no difference on our model currently.

5.3.1 Reset Auto Design Mode

The model is currently in check mode; beam sizes have been assigned and will now be checked against the revised analysis forces. To set the model back into auto design mode:

Select ‘Set Auto Design Mode’ from the “Design” drop down menu.

For all the structural elements listed, select the option for “All”, except for Braces.

“Validate” and “Design” the structure again – you may need to ‘update column load reductions’ before this can be completed. This is found under the “Building” drop down menu.

The nodal deflections obtained when diaphragm action is applied to the structure, has contributed to a small reduction but the results are still excessive and the structure unstable. Clearly a diaphragm simply distributes the forces to the vertical braced bays in the model in order to find the path to ground. Since we have no form of vertical bracing and the columns are pinned they are still able to fall over. Thus vertical bracing in the form of permanent or temporary bracing is required in order to complete our gravity design for this model. We will provide this lateral stability in the form of steel bracing.

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Lateral movement under gravity loading Creating Frame Views – 2D Elevations


5.4 Creating Frame Views – 2D Elevations

5.4.1 Proposed Arrangement of the Vertical Bracing

Bracing can be placed in the model using the structure view by selecting individual nodes, but errors can be easily made when trying to select the correct node. Fastrak Building Designer allows 2D frames or elevation views to be created, by selecting the appropriate grid line that represents the elevation required then creating a frame of the selected gridline.

Select the “Base-2D “ view

Use the “Select” and “Grid“ tool to select any gridlines you wish to create a frame view on.

Select Gridline A as show below.

Select “Create Frame(s)” from the “Buildings” drop down menu

Tension and Compression Bracing

Tension Only Cross Flats

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Lateral movement under gravity loading Creating Frame Views – 2D Elevations


Return to the “Project” pane window. You should see a plus sign next to frames

Expand the Frames area by clicking on the plus sign and you will see the newly created frames listed.

Double click on the Frame name or right click on the name and select Open Frame View from the right click menu will open a new workbook tab of the frame.

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Lateral movement under gravity loading Vertical Bracing


5.5 Vertical Bracing

5.5.1 Creating Bracing Attribute Sets

Bracing members can be automatically deigned in the ‘lateral sizing’ process. However the design of the section will be based on the load applied and not on the need to restrict deflections for lateral movement or sway stability. As such it is quite common for users to select bracing sizes rather than automatically design them.

Expand the Attributes for Bracing and create the following bracing types

General Title Type Size Design

Tension Only Rolled Beam Flat Bars 200x12.0 Gr 275 Accept Defaults

Tension and Compression Rolled Beam CHS 114.3x3.0 Gr 275 Accept Defaults

5.5.2 Creating Bracing Elements

The principle of applying bracing or any other structural element is the same as beams or columns. Set the required attribute

set to be the default, pick “Create” from the Select toolbar and “Bracing” from the Building Objects toolbar and click on the nodes to place bracing to and from the nodal points.

Select Frame A

Set the relevant Attribute Set as “Default”

Select “Create” and then “Bracing”

Create the following bracing pattern.

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Lateral movement under gravity loading Vertical Bracing


Complete the remaining bracing in the 3D view, it can help to switch off the full rendered ‘solid’ view and select the ‘wire’ option for ease of selecting the relevant intersection points.

The 3D view of the structure with bracing:

“Validate” the structure again

You will find that the structure has 2 warnings relating to cross bracing.

Cross braces are both active. There is no such thing as a tension only element in elastic analysis (a tension only element being a non-linear property). If these members were cross UC’s which will take compression then this warning can be ignored. If these members are cross flats that will not take compression then action should be taken to ensure an effective design.

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Lateral movement under gravity loading Tension Only Bracing


5.6 Tension Only Bracing

5.6.1 Analysis and Design Theory

Effective design of tension only bracing systems requires a pragmatic approach in multi-storey buildings. Comprehensive solutions to tension only analysis requires the use of a non linear analysis engine (such as the Full Newton Rhapson approach used in S-Frame), however such methods fail to work effectively when the building is subject to significant vertical load in combination with lateral load. This is due to the fact that during the analysis, columns suffer from axial shortening in load combinations that include significant vertical load, such as Dead + Super + NHL. When the columns shorten then both braces become subject to compressive loads which results in both braces becoming inactive. In fact this can happen under simple elastic analysis. The pragmatic solution that has been implemented in Fastrak requires you to mark one of the braces as ‘inactive’ if the X brace is a ‘tension’ only system. If your braces can be loaded in compression as well as tension, then leave both braces active.

Is this model correct?

It is a pragmatic solution, if you mark a brace as inactive, the design of the brace will be in tension only. Since an elastic analysis has no concept of strength (displacement is simply force/area) then the design of the braces and any displacements will be correct (as long as the braces go from floor to floor).

What happens if I in-activate the ‘wrong’ brace?

The effect of selecting the ‘wrong’ inactive brace will essentially send the lateral load down the wrong column of a braced pair of columns and could produce the incorrect load in a braced column and correspondingly the wrong base reactions For the purposes of initial design scheme often this issue can largely be ignored. Once you come to carry out the final design you can reverse the selection of the active brace. This will ensure that you have not under designed any columns and will enable you to select the appropriate foundation loads.

What should I do?

Simple Approach The simple one where the user simply assumes that whatever load can occur in the left hand column/base can also occur in the right hand column base. In the case of a simple model this might be done by ensuring that both columns are the same size and that the foundation loads of the ‘braced’ base are used for both bases. This method has its limitations; particularly where the building geometry is complex and twisting may occur. As such its use must be underpinned by engineering judgment. Comprehensive Check If you are not comfortable taking the simple assumption or you have a complex model then you should: • Carry out two design passes or create the output from two models. In one pass/model you would select the active combinations to create tension in the +X and +Y direction whilst selecting the corresponding active braces. • You then have a second pass/model creating tension in the –X and –Y direction with the corresponding active braces. • Note that you can change the setting for the active brace in a single action by using the ‘Show/Alter state’ and selecting all relevant braces with a box selection.

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5.6.2 Setting Braces as In-active

Click the “Show/Alter State” icon

Choose “Active Brace”, and click on one of each pair of cross braces so that it’s not included in the analysis.

Alternatively, make the braces in-active using the Select command and the Properties Window or edit the individual

properties of the brace.

Set all the BEAM and COLUMN elements back to “Auto Design” mode. (We do not wish to change the specified brace sizes to an auto design in this instance).

“Validate” the structure again. The output window should report back that the structure is valid.

“Design” all the elements in the structure.

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5.6.3 Revised Max Nodal Deflection Check

After the design process has completed review the max nodal deflections to ensure that the analysis results are valid and that you do not have excessive lateral movement which could indicate a mechanism in your model.

You will see that by applying a diaphragm to the floor plate (to effectively triangulate the plan area) and providing vertical bracing we have considerably reduced the nodal deflections in the global axis. Note – if a diaphragm had not been applied, the floor plate would need to have been triangulated in the x and y direction by the use of horizontal wind girders. With these reported global defections being acceptable we can be confident with the elastic analysis forces generated for the individual elements and can thus review individual element design results.

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Design and Analysis Results Tension Only Bracing


6.0 Design and Analysis Results

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Design and Analysis Results Loading Summary Tables


6.1 Loading Summary Tables

Once the max nodal deflections have been confirmed and accepted, the next area of the results tree which has to be evaluated is the loading summary. The loading summary is simply a mathematical double check. Does the sum of the applied load equal the sum of the base reactions?

The loading summary is broken down into each load case and the loading is broken down into every individual loading type.

If the discrepancy in the loading summary between the total load and the total reaction is minimal (say a few kNs) this may be put down to 3D modelling tolerances. But if the discrepancy between the values quoted is vast, then this will need to be investigated and then confirmed before you proceed.

If there is a discrepancy identified by the loading summary but the max nodal deflections noted above seem reasonable, you may need to contact your local CSC support department for help assessing the problem.

No sway results for the structure will be accounted for since the NHF’s to be included in the analysis were excluded in the Design Options.

Check in the loading summary that the load applied equals the base reaction for that loadcase.

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Design and Analysis Results Individual Elements Design and Results


6.2 Individual Elements Design and Results

Once the assessment of the max nodal deflections and the loading summary has been accepted and confirmed, then the individual elements making up the structure can be investigated.

6.2.1 Results via the Workspace Window

The individual elements are arranged in the order of beams first (general, simple, composite) listed in the floor level starting from the top down. Then the columns (general, simple) and then finally the bracing. Every structural element listed will have its Building Designer reference along with the designed section size and grade beneath it. To locate a member in the model:

Change to the “Structure-3D“ view.

Right-click over any beam reference name in the Workspace Window and select Highlight.

In this example, the majority of the model is passing – colour coded green. There are a few beams which has been coloured in amber which indicates that there is a warning associated with it. To obtain the individual result of an element listed in the workspace window, double click on the element reference name and the Design Summary dialog box will be displayed.

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Design and Analysis Results Individual Elements Design and Results


6.2.2 Example Results for a Simple Beam

6.2.3 Example Results for a General Beam

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Design and Analysis Results Graphical Results – Right-Click Options


6.3 Graphical Results – Right-Click Options

Until now all the results obtained for the structural elements have been retrieved from the Workspace Window. It is also possible to obtain results from the workbook area by the use of the right click menu. First, select the structural element type you wish to review from the Object toolbar (in this case Beam).

Then hover over the element you wish to review in the model and it will highlight in green. A tool tip will appear containing useful information. The amount of information displayed is controlled by the level of information you set for tool tips.

Select “Beams” from the Objects toolbar and hover over a beam in the model. Right-click over the highlighted beam to display the pop up menu.

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Exit Operation – Exits the right click menu without undertaking a task Zoom Area – Allows the user to specify a box over part of the model. The program will then zoom into this box area. Edit - Opens the individual properties of the element to allow modification. Design Results – Opens the Design Summary Dialog box for the selected element. Analysis Results & Reports – See below

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6.3.1 Analysis Results

The analysis results (shear, bending, axial, deflection diagrams etc.) for the highlighted element can be displayed in the workbook area once the model has been designed. The Analysis Results work in conjunction with the Loadings and Output toolbars.

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The Illustration below shows the individual analysis results for major axis shear and bending.

Loading on the Beam

Deflections

Moment

Shear

Loadcase or Combination you wish to visualise

View Options with Scroll bar Showing Values

Graphical Output Diagram Type

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6.3.2 Reports

Selecting the report option from the right click menu will generate a summary report workbook view. The report level can be altered via Show/Alter state – report level and setting the element as Reduced or Full. Re-creating the report via the right click menu will re-create the report based on the new report level. Below you will see selected elements of a report for a Simple Beam (Headers and Footers omitted)

REFERENCE: SB 2/3/A-2/3/Ba

Beam

Section Size, Grade

Span, L

[m] Rolled, UB 686x254x125, S275 10.500

Design Summary

Design Condition Status Combination Critical Value Capacity\Limit Units Ratio Class Pass 1 Class 1

Shear Vertical Pass 1 -386.6 1261.1 kN 0.31

Shear Web Buckling Pass 1 52.573 71.309 n/a

Moment Pass 1 1003.5 1058.4 kNm 0.95

Buckling Pass 1 1003.5 1061.5 kNm 0.95

Deflection Pass 1 17.8 21.0 mm 0.85

Notes Warning

ULS Composite Stage

Classification check

Item Value Units Clause of BS 5950 Flange Class Class 1 Plastic Table 11

Web Class Class 1 Plastic Table 11

Section Class Class 1 Plastic Part 1: 3.5

Pass

Vertical Shear check

Support Critical Value Capacity Units Ratio Status Lh Support 279.5 1261.1 kN 0.22 Pass

Rh Support -386.6 1261.1 kN 0.31 Pass

Shear Web Buckling

Item Value Units Clause of BS 5950 Depth to thickness ratio, d/t 52.573

Depth to thickness ratio limit, d/tlimit 71.309

Pass

Moment check

Position Critical Value Capacity Units Ratio Status 3.000 m 789.8 1058.4 kNm 0.75 Pass

3.500 m 877.0 1058.4 kNm 0.83 Pass

6.000 m 1003.5 1058.4 kNm 0.95 Pass

7.000 m 927.1 1058.4 kNm 0.88 Pass

9.000 m 558.7 1058.4 kNm 0.53 Pass

Deflection check

Condition Critical Value Limit Units Ratio Status Dead 17.8 21.0 mm 0.85 Pass

Imposed 13.7 29.2 mm 0.47 Pass

Total 31.4 52.5 mm 0.60 Pass

Lateral Torsional Buckling check

Sub Beam Critical Value Capacity Units Ratio Status

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Sub Beam Critical Value Capacity Units Ratio Status Sub Beam 1 789.8 1534.7 kNm 0.51 Pass

Sub Beam 2 877.0 1102.2 kNm 0.80 Pass

Sub Beam 3 1003.5 1061.5 kNm 0.95 Pass

Sub Beam 4 1003.5 1091.5 kNm 0.92 Pass

Sub Beam 5 927.1 1247.6 kNm 0.74 Pass

Sub Beam 6 558.7 1744.2 kNm 0.32 Pass

Loading diagram

0.000 3.0003.500

5.340 6.000 7.000 9.000 10.500

Shear diagram279.5kN

-386.6kN

0.000 3.0003.500

5.340 6.000 7.000 9.000 10.500

Moment diagram1003.5kNm

0.000 3.0003.500

5.340 6.000 7.000 9.000 10.500

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Design and Analysis Results Graphical 3D Model Analysis Options


6.4 Graphical 3D Model Analysis Options

In addition to viewing analysis results individually for any structural element, you can also view the analysis results for the entire 3D model. You can select from various options on the Output Graphics toolbar and view the results by loadcase or combination.

6.4.1 Output Graphics Toolbar

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Ensure that you are currently in a Structure-3D view of the structure

Select “Shear Major” from the Output toolbar.

The following Post Process Operation will occur.

A 3D representation of the major shear forces are displayed for the structure.

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The analysis forces being displayed are controlled by the loadcase or combination that you have currently set in the Loadings toolbar

6.4.2 Diagram Scaling

The graphical representation of the analysis results can be scaled for better clarity on the screen.

Hold the “CTRL” button on the keyboard

Then “SCROLL” the “WHEEL” on the mouse controller.

This will scale the diagram on the screen.

Loadcases Option

Combinations Option

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6.4.3 Changing the Analysis Output Colours

From the file down menu select “Preferences” then the “Colours” option

Select the “Results Graphics” option

Change the colour of “Shear Major” and then Press OK

6.4.4 Displaying Extreme Analysis Values on the 3D diagram

Numerical analysis values can be shown graphically on the screen. These values are controlled by View Options.

Access the “View Options”

Under the Text tab select the option for “Extreme Values”

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6.4.5 Example Analysis 3D Diagrams

Major Axis Shear (ULS Load Combination) Major Axis Bending (ULS Load Combination)

Minor Axis Shear (ULS Load Combination) Minor Axis Bending (ULS Load Combination)

Axial Force (ULS Load Combination) Torsional Forces (ULS Load Combination)

Reactions (ULS Load Combination) Deflected Shape (ULS Load Combination)

Sway Deflections (ULS Load Combination)

The View Options criteria that can be set for deflections

No Results are shown for Sway Deflections since NHF’s were not included in the analysis

All diagrams displayed will have additional criteria that can be set in the View Options dialog box

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Graphical 3D Model Analysis Options


7.0 Adding Upper Storeys

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Adding Upper Storeys Adding Duplicate Floors


7.1 Adding Duplicate Floors

Once the gravity design of a single floor has been rationalised and completed we then copy the floor up to the upper levels, as required, to complete our structural model geometry.

7.1.1 Creating Additional Construction Levels

Select “Levels” from the Building menu.

Highlight Roof and rename as 1st Floor and change the level value from 3m to 4.00 m

With a cell selected on the new 1st Floor level press the “Insert Above” button twice

New levels will appear shown in red.

Set “Level No.2 = 8.00 m” and “Name = 2nd Floor”

Set “Level No.3= 12.00 m” and “Name = Roof”

Click “OK” to set the new construction levels

Obtain a Structure-3D view and ensure that your grids are turned on in the View Options.

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7.1.2 Copying Floors

Now that the construction levels have been established, the original level can be copied to the upper floors.

Select “Copy Floor” from the Building drop down menu

Select the Source level as “1st Floor” i.e. the Level you wish to copy.

Then select the Destination Levels of “2nd Floor and Roof” by ensuring a tick in the Copy To column.

Finally select all the Objects from the source level that you would like to copy and click “OK”.

The Structure-3D view will be updated to show the new copied construction levels.

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7.1.3 Extending Columns

You will note that the columns have remained at the original start and finish construction levels and were not extended when we added additional construction levels.

In the Structure-3D view use “Select” and “Column” from the Select and Object toolbar

Select all “19 columns” individually or by dragging a window around the model.

Note: Remember to clear the selection after pressing the Select and Columns icons to ensure you are starting your selection from zero.

Select “Column Levels” from the Building drop down menu

In the Column levels dialog set the columns to start at the “Base” and finish at the “Roof” levels.

Click OK and the column level end will be adjusted to finish at the roof level:

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7.1.4 Copy Bracing Elements to the Upper Storeys

The bracing elements were not copied up earlier and thus only exist at stack 1 (between Base and 1st

Floor level) of the columns. We therefore need to copy them up so they also exist at stack 2 and 3. To make the selection of the bracing elements easier we will use View Options to hide the upper floors and reduce the model back to show only the base level. This means that the base level and those elements connected to the base level will be displayed.

Select “View Options”

Reduce the visible storey levels by unchecking everything except the Base level via the Floors tab

Select “Copy Elements” from the Building menu

Select all the bracing elements by singularly clicking on them to ensure that all “6 braces” are selected or by selecting Brace from the Object toolbar to isolate the selection to braces only and box a window.

Click “Next” to move to the Set-out dialog and select the set-out point for the copy.

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In the Mirroring dialog select “no mirroring” and click Next

In the Rotation angle dialog leave the rotation at “0deg” as we do not wish to rotate the bracing in this instance.

Finally in the Target Dialog select the Insertion point of the copy i.e. as the screenshot below.

Once you are happy with the display – click Finish to actually place the elements in the model.

Because we have set View Options to only show the Base level and these new braces will not be displayed until we turn back on the 1

st Floor, 2nd Floor and Roof levels

Select View Options – “Floors” tab and turn back on all the floors

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Adding Upper Storeys Completing the Gravity Design


7.2 Completing the Gravity Design

Now that the entire structure has been created, the columns of the structure will need to be re-designed again to allow for the extra floors of loading.

Select “Set to Auto Design Mode” from the Design menu (or use Show/Alter State – Autodesign)

Set the following preferences

This will allow the columns to be redesigned while the beams will be re-checked.

“Validate” the model

“Design” the model.

Check the design status of your model via the workspace results view. Are the max nodal deflections acceptable? Is the basic loading summary acceptable?

Once these have been checked and verified review the Show/Alter State - where all members should be passing. If any members are not passing review and action.

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Frame Imperfections and Sway Completing the Gravity Design


8.0 Frame Imperfections and Sway

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Frame Imperfections and Sway Imperfections and Sway Introduction


8.1 Imperfections and Sway Introduction

BS5950-1:2000 clearly states that NHF’s (Notional Horizontal Forces) will be applied in the assessment of the structure in two distinct areas: Practical Imperfections: To allow for the possibilities that structural elements may not be absolutely straight or erected perfectly vertically. Notional Horizontal Forces are applied to mimic such effects. Sway Stiffness Analysis: Notional Horizontal Forces are applied to the model, to simulate notional horizontal deflections for each storey in the model.

To evaluate the sway susceptibility of the model and determine the elastic critical buckling factor (cr)

The use of NHF’s and Storey Drift has been shown to be a very accurate prediction for cr in multi-storey structures but cannot be used for all structural shapes such as some portal frames. For more clarification and information please refer to BS5950-1:2000, or contact CSC Support

8.1.1 Notional Horizontal Forces

Notional Horizontal Forces, otherwise known as NHF’s, are defined as being the minimum of 0.5% factored vertical dead load and live load applied at the same level. Notional horizontal forces should be assumed to be acting in any one direction at a time and combined with load combination 1: Dead Load and Imposed Load (Gravity Loading). See clause BS5950-1:2000, 2.4.2.4 and 2.4.1.2. Please note when considering NHF’s in combination 1 above they should NOT:

Be applied when considering overturning:

Be applied when considering pattern loading:

Be combined with applied horizontal loading:

Be combined with temperature effects:

Be taken to contribute to the net reactions at the foundations:

8.2 Practical Imperfections

To allow for the effects of practical imperfections to the structure, such as fabrication, erection and the lack of verticality, all structures should be capable of resisting notional horizontal forces. Notional Horizontal Forces are derived as being the minimum of 0.5% factored vertical dead load and live load The derived NHF’s in the above context are combined with factored gravity loading with in a combination. It is important to realise that NHF’s may exceed wind loads. Notional horizontal forces should not be combined with any other lateral forces within the loading combination (e.g. wind loads) BS5950:2000 applies NHF forces in a 2D nature i.e. X and Y axes. To allow for the reversal of forces in bracing and the natural twist in any structure, NHF’s are recommended to be applied in four directions X+, X-, Y+ and Y-. The application of the above procedure is not second order effects.

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Frame Imperfections and Sway Sway Sensitivity Analysis. P-Delta Effects


8.3 Sway Sensitivity Analysis. P-Delta Effects

It is important to consider the basic concepts of structural behaviour and appreciate the intentions of BS5950-1:2000. Second order effects or otherwise known as P-Delta effects are those which can affect local individual members as well as global movement of the entire structure. These non linear effects will occur in every structure when an element is subjected to an axial load.

8.3.1 Local p-delta buckling (p

Individual members can exhibit local deformation due to the slenderness or imperfections of the member. Therefore acting on the

original centre line of the beam.

Where the action of the axial force is known as (p)

Eccentricity of the member to the original line of action is known as ()

8.3.2 Global P-Delta buckling (P

Lateral force (A) applied to a structure will instigate movement and natural sway deflections. This can also exhibit PΔ effects when axially loaded elements (P) are subjected to an eccentricity (Δ). All PΔ effects will have to be assessed and verified if instabilities are an issue which may also occur in the global condition from frame imperfections.

P

A

Notional Horizontal Forces are applied to the model, to simulate notional horizontal deflections for each storey in

the model. To evaluate the sway susceptibility of the model and determine the elastic critical buckling factor (cr)

The lateral force is the same derived NHF’s used previously for framing imperfections in multi-storey buildings.

(cr) Elastic Critical Buckling Factor is used to assess the instability caused by second order.

The elastic critical buckling factor is the factored number in which the combination of ultimate limit state (1.4 Dead + 1.6 Live + A(ULS)) would have to be factored to cause an elastic buckling of the frame in a sway mode.

Elastic Critical Buckling Factor lambda crit, (cr) is derived by the equation:

p

Local p-delta buckling (p)

Global P-Delta buckling (P)

Where A, - Lateral force applied to structure P – Axially loaded element

Eccentricity of the applied axial force.

cr = h /200

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8.3.3 Sway or None Sway Susceptibility and Evaluation of cr Results

From the assessment of the value obtained from lambda crit (cr) we can determine the sway sensitivity of the structure in conjunction with the loading applied.

A true check for cr requires the software to establish the drift of every column in the structural model in all directions.

Fastrak Building Designer will automatically report back any twists in the structure which would be missed by a simple 2D analysis method.

In the context of BS5950:2000, the categorisation on whether the frame in the direction of the applied loading is to be determined as a Sway or Non-Sway frame depends on the magnitude of the loading and the stiffness of the frame in that direction.

The Categories of Sway and Non-Sway are established from the lowest critical load factor, cr of the frame in the

sway mode. The position along the column where to establish the value of cr, is usually between the base level and the first storey (∂1-∂0, where ∂0=0 pinned base) but this depends on the model created.

8.3.4 Non Sway Sensitive Frames (cr > 10)

Once cr, has been derived and a value obtained that (cr > 10) you can now classify the frame in that particular direction as being “Non Sway Sensitive”

This signifies that the stiffness in the direction of the lateral load is substantial and that the resulting (PΔ) effects are

minimal. The resulting value of the elastic buckling load factor cr, is greater than the value 10, indicating a large multiplication of the ULS combination to instigate an elastic critical buckling of the frame in a sway mode.

8.3.5 Sway Sensitive frames (4 < cr < 10)

If values obtained for the elastic critical factor lambda crit cr range between 4 and 10, the classification of the frames in this particular direction are “Sway Sensitive Frames”

Therefore the elastic linear analysis has to be modified to take into consideration these effects. There are 3 methods available to you in the code which you can adopt:

1) Modified Effective Lengths Method (Annex E BS5950:2000) - The effective lengths of the columns in the sway mode are adjusted using figure E2 contained in Annex E BS:5950:2000 – This method is only intended for use in moment frames and is NOT used in Fastrak Building Designer

2) Amplified Forces Method (Kamp) - A multiplication factor is derived and is then applied to all forces which induce this sway effect.

3) Use a ‘true’ second order analysis such as the two step iterative approach.

PROVIDED THAT IT IS ACCEPTABLE WE ADVISE THAT YOU USE THE Kamp APPROACH IN FASTRAK BUILDING DESIGNER

WHEN SWAY SENSITIVTY IS CRITICAL (4 < cr < 10)

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8.3.6 The Amplified Moments Method, the Kamp Approach.

The derived amplification factor which is applied to the forces inducing the sway of the building is determined in one of 2 ways, depending on the cladding of the structure.

The building is clad and the stiffening effect of the cladding is ignored.

5.115.1

cr

cr

ampK

Must be greater or equal to 1

The building is unclad or is clad and the stiffening effect of the cladding is taken into account.

1

cr

cr

ampK

Must be greater or equal to 1

8.3.7 Second Order Analysis required (cr < 4)

It is our recommendation that frames have cr >4 and that the Kamp method be used where possible.

If lambda Crit cr is less than 4 the classification of the frame is “Extremely Sway Sensitive”.

A full second order elastic analysis (the two step iterative analysis) should be adopted.

8.3.8 Options for Automatically Applying Kamp

The Second Order tab on the Combinations dialog controls the Kamp value used and the loads to which it is applied.

Is Automatic Kamp to be applied to this combination?

The cr for this combination will be obtained in the global x direction

The cr for this combination will be obtained in the global y direction

The cr for this combination will be obtained from the average of x and y.

The cr for this combination will be obtained from the maximum of x ad y

Building Designer will default to the option of “the maximum direction of x and y”

Finally, now that cr is determined for the combination and the kamp formula

established, the option above allows the amplification to be applied to all

loadcases in the combination or only the lateral ones.

Building Designer will default to the option of “Lateral Loads Only”

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Frame Imperfections and Sway Creating Notional Horizontal Forces


8.4 Creating Notional Horizontal Forces

8.4.1 Calculating NHF’s

Fastrak Building Designer will automatically calculate the NHF’s.

When checking sway stability, these will be applied to the structure on their own and the relevant lambda crit. summaries will be reported.

8.4.2 Creating Combinations with NHF’s

In BS 5950 we are required to include NHF’s in combinations with vertical load only.

This is to allow for lack of fit and NOT sway stability.

Select “Combinations” from the Loading menu

Create a combination for “Self-weight + Slab dry + Imposed + Various Dead + NHF X+“

Repeat the above process for the other 3 NHF directions

The Loadcase of NHF X+ has the multiplication factor of 1.0

The load combination generator may be used to create the 4 NHF combinations if required.

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Frame Imperfections and Sway Design Results for Frame Imperfections


8.5 Design Results for Frame Imperfections

Since we are interested in the lateral design of the model i.e. the braced bays resisting these NHF’s we will turn off the check design of the beams to speed up the analysis and design process. Since these beams have already been designed for gravity the lateral design will not affect them.

Select “Design Options” from the Design menu.

From the Design Control tab highlight the construction levels you do not wish to design and click on Selected Off to remove the ticks from the table. This will ensure only the sloped and vertical members will be designed.

“Validate” and perform a “Full Design Check” of the model

Review the workspace before reviewing the individual results in show/alter state.

Max Nodal Deflections

Loading Summary

Only then check the model to see if any structural elements are failing.

For this training example we will not correct the structural elements that are failing.

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Frame Imperfections and Sway Determination of Sway Sensitivity


8.6 Determination of Sway Sensitivity

When sway stability is being assessed, this invokes a separate sway assessment to be undertaken on the model during analysis and design. Upon completion of the design a new area for Sway appears in the workspace results tree.

When a First Order Elastic analysis is performed Fastrak Building Designer will check every column (unless you have excluded it from the sway checks) in the model for sway effects.

In the workspace window FTBD will report back the 2 critical columns which have the worst sway deflections in the global x axis and the global y axis.

To identify the column within the model, right click on the column name and select Highlight from the menu. To clear the highlight right click in the workbook area and select clear highlight from the menu.

To see the results for the critical column double click on the column name and review the summary tab and then the appropriate sway tab for the column you are reviewing

8.6.1 Viewing the Sway Results

Right-click over the “Sway X Critical” column name and select “Highlight” to locate it in the model

Select “Sway” from the Graphical Output toolbar to view the sway deflections

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Frame Imperfections and Sway Determination of Sway Sensitivity


8.6.2 Sway X Critical

Double click over the “Sway X Critical” column to open the sway results.

Ensure you are looking at the correct tab i.e. the “Summary” tab or the “Sway X” tab

In this example Crit crit x, Sway = 6.58 < 10 Sway Sensitive

8.6.3 Sway Y Critical

Double click over the “Sway Y Critical” column to open the sway results.

Ensure you are looking at the correct tab i.e. the “Summary” tab or the “Sway Y” tab

In this example Crit crit y, Sway = 11.31 > 10 Non-Sway Sensitive

Therefore for the model created we have a sway sensitive frame in the X direction

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Frame Imperfections and Sway Automatic Application of Kamp


8.7 Automatic Application of Kamp

Since we have determined that the model is Sway sensitive in the X direction we can change the analysis type to Second Order (P-Delta) analysis Kamp approach.

8.7.1 Setting the Auto-Kamp Formula Method

Select “Analysis Options” from the Design menu

Check the option for “Second Order P∆ Analysis”

Select the “Auto-Kamp formula” option of 5.115.1

cr

cr

ampK

Then press “OK”

8.7.2 Applying the Auto-Kamp

Select “Combinations” from the Loading menu

Edit the “ULS + NHF X+ “ Combination

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Frame Imperfections and Sway Automatic Application of Kamp


Select the option of Second order effects.

NOTE – this option will only appear if the Kamp P-Delta approach has been selected in the analysis options.

Ensure that “Auto Kamp” is ticked

Ensure the option for “the maximum direction of x and y” is selected

Ensure apply to “lateral loads only” is selected

“Validate” and “Perform Gravity Sizing” the model

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Frame Imperfections and Sway Sway Results


8.8 Sway Results

Check Max Nodal Deflections and then Loading Summary.

View the Sway results

As can be seen for the ULS combination cr established for the first combination indicates a sway sensitive frame in the x direction and a non sway frame in the y direction.

crit x = 6.583

crit y = 11.308

Kamp value = 1.084

(same values obtained previously)

Note crit values for wind combinations (if applied) would be less onerous than the ULS combination

For the combination of ULS +NHF Y+ a kamp value has been applied to the combination, even though that the model has been established as Non–Sway in the y direction.

This is due to the crit option for this combination being set as the maximum x or

y value.

For more information on NHF’s, Sway and P∆ Effects please refer to the advisory document “Building Designer Designing for Second-order Effects Advisory Note - V1.0.pdf”

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Reports and Drawings


9.0 Reports and Drawings

Material listings, drawings and paper report creation

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Reports and Drawings Reports


9.1 Reports

Before generating a report we need to tell the program which elements in the model we would like to include in the report. This can be achieved by either the show alter state graphical method, or via the Report Pane window. Both alternatives are demonstrated in the next sections.

9.1.1 Show Alter State Graphical Method

Access the Show/Alter State Graphical display by clicking on the show alter state icon

In the Show/Alter state dialog box displayed on the screen, go to the ‘Results’ tab and left click on the Report Level text

This switches the view to show the elements and their current report level status.

Select a traffic light on the right hand side of the dialog box to depict the level of report you want to assign to an element.

Click on an element or drag a window in the model to assign this level of report.

This will flag the selected element by giving it the same colour as the traffic light you chose, such that it will be included in any report generated. By inspecting the graphical view you can quickly determine the elements selected to be included in a report to be generated and their associated report level. All other elements are off i.e. they are not selected to be included in a report and hence no information pertaining to them will be generated.

Try assigning different report levels to some of the elements in your model.

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9.1.2 Workspace Report Area

The alternative to the show alter state graphical approach is the Report pane window.

In the window on the left hand side of the screen left click on the report tab highlighted on the screen capture.

This will display a tree structure of all the elements in the model and their current report status. These elements can then be included/excluded from report generation as appropriate. To access the sub-folders click on the + adjacent to the root folders/sub-folders. Every element in the model will be itemised under the appropriate sub-folder. To minimise the display click on the – adjacent to the root folder/sub-folder. The tree structure comprises – Summary – To provide a single line summary of the available construction types in the model. By default these are ticked to be included in the element design report. Construction Levels – All beams lying on the construction level are listed. Beams, Truss Members, Columns and Braces – All element types are grouped under the respective headings. Note: Beams relate to any beam that does not lie on a construction plane i.e. inclined beams.

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Expand the Construction Levels to access the Roof Beams folder.

You will note that the beams are designated with either a tick or cross to indicate if they are ‘flagged’ to be included or excluded from the report. The included beams relate are those we selected using the show alter state graphical method earlier. To include an element, right click over a currently excluded beam and then left click on the text displayed to change the elements status to be included.

Try including a beam element.

To assign the report content level of the now included element or to exclude it from the report, right click on the element again and a further right click menu appears. Left click over the text of the action you wish to perform.

Try excluding an element from a report and changing its report level.

The default report level is summary

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You may wish to quickly include or exclude all beams or columns from a particular heading. This can be achieved by right clicking on the heading and selecting the appropriate option.

To generate a column foundation report you will need to do this to include all the columns in the report generation otherwise you will generate a blank page.

Try including all columns and reviewing the status of the individual column elements.

Reset the report level to EXCLUDE the columns before proceeding.

9.1.3 Report Content

Before we generate a report, the report levels - Summary, Reduced and Full Output - can be customised to contain the information that you would like to show for the individual element report.

Pick File/Report Content

Customisation of these report levels is saved outside of the model and thus once set up can be used for all future models created.

The following dialog box is displayed

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The Element drop down box lists the available construction types. The report level drop down box lists the three available levels of report output.

Pick the Application whose report details you want to configure.

Pick the Report Level in which you are interested in altering.

If you wish, enhance the information for strength of serviceability checks (the defaults level is the design summary). Tick the Include Item Options which you want to include and select the level.

Once you have made your settings click OK to save and use these for this model and all future models.

If you are unsure about the style content of the output you wish, set it up on one member using the right click button to create a report for any given member.

9.1.4 Element Reports

Since elements have been ‘flagged’ to be included in a report along with an appropriate report level the report can now be generated.

Pick File/Report/Element Design to generate an Element Report (screenshot below).

By default the Element Design Report includes a single line summary of every element in the model in addition to the requested elements we flagged earlier. This can be turned off if required, via the Workspace report tab or through the Structure/Summary folder, found by right clicking on the Construction type title and excluding.

Take note of the other reports available within Building Designer

Try generating other reports by selecting a different report.

New tabs open in the Workbook area showing the requested report.

Remember only the elements flagged in the previous sections are included in a report so you may get a blank page if generating say base reactions or bracing!

You can view the contents of the generated reports by either using the vertical scroll bar or the icons available on the Navigation toolbar

Use the left and right arrows to scroll though the report, up arrow to go to the start and down arrow to go to the end of the document.

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You can alter the display of the report within the workbook via the Report toolbar

To print the displayed report. Pick File/Print.

Close the active tab by picking the smaller cross in the top right hand corner of the screen.

NOTE We would recommend that you initially generate an Element Design Report with no elements flagged for inclusion in your report. Inspect this ‘Summary’ report to determine the most critical elements in your model and then flag those you would like to be included in the report along with the appropriate level to minimise paper output. You will need to regenerate the report to add the additional elements.

A range of reports are available for the Beam End Reactions and Base Reaction Reports including max/min reactions reports that you select from the workspace.

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9.1.5 Exporting Results to Excel

Pick File/Export/Export Base Reactions to Excel to generate an Excel Report.

Before outputting to excel you must select the relevant level of output from the workspace.

Note You must select the appropriate output for items such as base reactions and beam end reaction. Lc = Load case Fact. Cb = Factored combination Unf. Cb = Unfactored combination Therefore in the screen to the right I have selected beam and forces for all load cases and a max/min summary of the combinations. IMPORTANT Max/Min and Max/Min + coincident values should not be considered with ‘critical combination’ if in doubt you should consider all load combination.

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You will note that the Excel spreadsheet contains tabs to cover Load Cases, Unfactored Combinations and Factored Combinations to assist in the steel base plate design and foundation design.

Pick File/Export/Export Beam End reactions to Excel to generate an Excel Report.

Close the Excel Spreadsheets and return to Fastrak Building Designer.

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9.1.6 Material Listing

Material Lists can be viewed on the screen, generated as reports for printing, or exported to Excel spreadsheets for manipulation/printing. You can inspect the information pertaining to each element in the model. The list can be reduced to contain just the information you require by altering the element type and location drop down boxes to suit. A total steel weight is displayed at the bottom of the Total Weight Column.

Pick Material Listing from the Design drop down menu.

Try changing the Element type and Location and review the rows and columns in the table displayed.

Tabs are also available across the top to review Steel, Concrete and Floored Areas.

Click OK or Cancel to exit out of the Material Listing Dialog.

To generate a Material Report

Pick File/Report/Material Listings.

An alternative is to export the Material Listing data to Excel in order to undertake further manipulation of the data.

Pick File/Export/Export Material Listing to Excel to generate an excel spreadsheet containing the material list data for the model.

Review the Excel Spreadsheet then close it and return to Fastrak Building Designer.

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Reports and Drawings Drawings


9.2 Drawings

9.2.1 DXF Plans and Elevations

AutoCAD DXF plans and frames can be generated that can then be viewed and further manipulated using your preferred DXF compatible drawing package.

Select the workbook tab of the Plan or Frame you wish to export so that it is visible in the Workbook area.

If the tab is not available for the view you wish to create simply double click on a frame or construction level in the Workspace Geometry tree structure.

Select the load case or load combination from the drop down box that you would like to export beam end reactions and column base reactions for.

Pick File/Export/Export to DXF

You may be prompted with a ‘save as’ dialog box where you can choose the location to save the file.

A file name is automatically generated for you in the format: Job Name_Construction Level_Load Case/Combination.dxf. You can overwrite this with your own filename if you wish.

Browse to a folder you want to save the file and change the drawing name or accept the default and click OK

A DXF Settings dialog box appears asking you for text height and spacing values

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Using the DXF layers and DXF Objects tabs you can assign Building Designer objects to the AutoCAD Layering standards that you wish to support.

You can choose to save these settings along with the text sizes and export details so that they are remembered the next time you wish to export to DXF.

Accept the defaults and click OK to create the DXF drawing file.

If you have AutoCAD or a compatible DXF reader on your computer you can open the package and browse to the DXF file to open it.

A part extract of a DXF plan of the Roof Level is shown below for information showing the information split into layers.

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Grids, Grid Names, Element Reference and Serial Size, Composite transverse reinforcement, Slab and decking information and beam end reactions/column base reactions are all exported and placed on independent layers in the drawing.

A 3D DXF export is available by selecting a DXF export while viewing the 3D model.

9.2.2 3D Model

If you have CSC 3D+ (which uses the industry leading AutoCAD platform), it is possible to export the entire 3D model.

You will then, amongst many other things, be able to create general arrangement views of any plane of the model and undertake change control if changes occur.

Beam End Reactions etc. can be filtered to determine the most critical combination for connection design and reported on the GA drawings

A model could be created in 3D+ by a draftsman then imported in Fastrak Building Designer for design – saving the Engineer the time spent inputting a model.

Significant time savings and other control benefits can be made using Building Designer with 3D+. If this is something you would be interested in discussing please contact your local CSC office for further information.

Pick File/Export/Export to 3D+ and provide a folder and name for the 3D+ Neutral file

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Reports and Drawings Export Options


You Trainer will show the exported the model in 3D+ and the generation of a couple of planes through the model if time allows.

9.3 Export Options

Export to other programs is available via the File/Export menu.

Export to Excel (Material, Beam End Reaction and Column Base Reactions), Export to DXF and Export to 3D+ were covered in the preceding report sections. Please refer to the respective sections of the manual.

Export to S-Frame allows the model to be exported to our high level analysis package where further investigation such as buckling, meshing of core walls, vibration analysis and non-linear analysis can be investigated.

Export of 3D models to Autodesk Revit Structure allows ‘round tripping’ of the model to purpose built BIM (building information modelling) software. This is covered in more detail on the Fastrak Building Designer Day 2 Advanced training course.

Further export options are also available which are referred to via the online help system. Pick Help/Help Topics for further information.

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Lateral Loading Export Options


10.0 Lateral Loading

185

Lateral Loading Lateral Wind Loading


10.1 Lateral Wind Loading

In Fastrak Building Designer, lateral wind loads can either be manually applied to the structure or automatically applied with the additional purchase of the Fastrak Wind Modeller module. In this standard training course we will apply lateral loading manually. The application of the Fastrak Wind Modeller is included in the Fastrak Building Designer Day 2 course. Manually, the loading can be applied by nodal or element load, or by area loads using the Simple Wind Load command.

Create two new loadcases called “Wind In X” and “Wind In Y” and ensure that they are defined as type “Wind”.

Select the “Wind in X” Loadcase in the drop down box and create a Frame of Gridline A

Please note that the Frame A was already created when the lateral bracing system was applied to the building.

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Lateral Loading Variable Lateral Loading Possibilities


10.2 Variable Lateral Loading Possibilities

The Variable Lateral Loading Possibilities section is for information only

10.2.1 Wind Nodal Point Loads

Nodal point loads can be placed at beam/column intersection points to place a lateral load on the structure. If a nodal load is placed at a position where the load cannot be decomposed errors will be reported in the loading summary breakdown and the validation report.

10.2.2 Element Loading

Structural members can be individually loaded to transmit the lateral forces into the building. Please note that the structural members in question (beams and columns) will be loaded on there minor axis therefore most of the objects will have to be general in nature.

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10.2.3 Roof’s Applying and Adjusting

Roofing elements allows the decomposition of loading to the surrounding structural elements in a single spanning manner. These roofing items can be placed in horizontal or sloping planes but must be surrounded by structural steelwork and must be planer. The roofing objects are placed on the structure by selecting the individual node points in sequence back to the initial point to create the roof.

The roofing element is displayed above showing the span direction of the element. If this direction needs to be changed, the panel has to be selected and the span direction needs to be changed using the properties window.

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10.2.4 Application of Area Loading to Roofing Elements

Once the single spanning roofing elements are applied to the model these can be loaded using the area loads option. The area loads option will allow positive and negative directions of loading, with options of normal (On sloped area) and vertical (On Plan Area) loading.

Example of roof loadings

Area Load Normal (On Sloped Area) Area Load Vertical (On Plan Area)

Negative Area Load Normal (On Sloped Area) Negative Area Load Vertical (On Plan Area)

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10.2.5 Applying Wind Walls and Using the Wind Load Generator

Since roofing elements can be applied to horizontal and inclined planes there is another loading item which applies area loading to vertical upright planes. The wind wall is a 2 way loading distributing item which allows a lateral loading in the form of kN/m

2 to be applied to a face. The wind wall will then automatically decompose the loading into nodal or element loads.

Note: Element loads decomposed from wind loads are intended to be used for generating UDLs on portal stanchions and gable posts without the need to model side rails.

Wind walls must be placed in rectangular or triangular shaped arrangements. Again using the create action and selecting the node positions that form the shape. Triangular shaped Wind Wall Rectangular shaped Wind Wall

Rectangular Wind Walls can be placed by just selecting the diagonal node points.

First Click Second Click

Please Note when roof’s and wind walls are applied to the model, these items are finite element panels and will therefore will apply no additional loading placing these objects.

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Nodal Loads

Begin by selecting the wind loadcase from the loading toolbar. Next activate the wind load generator by choosing the “Loading” drop down command and then “Simple Wind Loading”.

In the simple wind loading dialog box enter the height of the building and the magnitude of the force that has to be applied to the panel. Ensure that you enter the correct angular direction and length/level to apply the force

When you press the ok button a wind pattern and the nodal forces will be applied to the beam column intersection points.

0 Degrees

270 Degrees Degrees

180 Degrees

90 Degrees

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Once the nodal loads have been generated on the structure, the wind walls placed can be deleted. It is good practice to contain one wind load angle in an individual loadcase.

Element Loads

Walls have an attribute that determines whether wind loads applied to them are distributed as UDL’s or point loads to supporting members. This will allow the generation of UDL’s on portal stanchions and gable posts from walls without the need to model side rails. To edit this property on a wall, simply select one or more walls and ‘Decompose Member’ option shown below. When set to yes the wall will generate UDL’s on columns as shown. When set to 'No' the wall will decompose point loads to the beam/column intersections as before.

By definition UDL’s cannot be applied to simple columns and hence care should be taken when using To set the ‘decompose member’ to no when applying wind load on walls which are connected to ‘Simple columns’. Using this option will apply point loads at the beam column connections – i.e. at each floor level and not between floors.

Wind Loading Pattern and Direction Check

Nodal Loading Applied to the structure

192

Lateral Loading The Simple Wind Load Generator


10.3 The Simple Wind Load Generator

10.3.1 Application of nodal loads

Ensure that the two loadcases of Wind in X and Wind in Y have been created.

Select “Wind in X”

Then Select the option of “Create” and then “Wind Load” from the Loads toolbar.

Establish the frame view of Gridline A

Place the nodal loads on the frame as shown below, either by dragging a window to select several nodes or by the single clicking of the beam column intersection points.

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10.3.2 Wind load Generator

Before the Wind Load Generator can be used we need to establish on the model the Wind Wall Distribution Panels.

Select the “Create” button and then “Walls” on the Object toolbar

By selecting the node points place wind walls on the following elevations

Select the loadcase “Wind in Y” from the loading toolbar.

Then select the “Simply Wind Loading” option from the “Loading” drop down menu

Enter the following values into the dialog box.

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Ensure the wind loading pattern is being applied as below.

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10.3.3 Creating Wind Loading Combinations and Re-evaluating the Structure

Under the loading combinations dialog box create the following combinations

Add a similar load combination for Wind in Y

Validate and check the model using the ‘Perform Full Design’ option.

Recheck the max nodal deflections and the loading summary

Then ensure that all members pass.

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Composite Floor Design The Simple Wind Load Generator


11.0 Composite Floor Design

Composite design

199

Composite Floor Design Composite Floor


11.1 Composite Floor

We will consider one half of the roof floor plate as composite, see the 2D structure layout below.

The external beams around the perimeter will stay as simple in construction.

The internal beams comprising the floor will be changed into composite beams.

Before we begin it is very important to understand that BS5950-3.1:1990 has received a safety amendment and has now become BS5950-3.1:1990 + A1:2010 which is mandatory for future British Standard Designs.

Doubts had been raised about the design model for composite beams, specifically associated with the strength of studs when used with trapezoidal decks. The key issues that the safety amendment covers are;

Maximum 2 studs per group.

Stud strengths reduced (significantly in some circumstances).

New interaction rules.

New ‘higher ductility’ shear stud – note this is not a new stud, but a new design condition.

In some cases effective composite design can be more difficult, though this is beam span and deck type dependant.

Fastrak has added an optional auto design of a ‘simple beam’ if composite fails.

In some cases (long span beams) design may be ‘easier’ to achieve.

Value engineering even more critical.

Impact of deck type (trapezoidal v re-entrant) is more significant. For further information on the changes please refer to BS5950-3.1:1990 + A1:2010 YOU control what preferences the software sets upon starting a new model via File > Preferences. We can however, change design codes (see later chapter) to design our structure to alternative design codes at will. We will check to ensure that the composite design for this model is using the new A1 amendment before we carry on.

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Access Design > Design Options > Design Codes tab and ensure Composite Code = “BS5950-3.1:1990 +A1:2010”. Click Ok. Accept any warnings you may receive about the impact of changing the design code.

For the following example we are going to iterate a solution, so we are going to opt to turn off the optional “auto design of a simple beam if composite fails” option.

Access Design > Design Options > Composite tab and ensure “allow automatic design of composite to non-composite if no section satisfies design criteria” is unchecked.

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11.1.1 Creating a Composite Beam Attribute Set

Create the following attribute for Composite Beams.

General Design Alignment Type Support Size Reinforcement

Composite Beam Gr 355 No-

Reinforcement

Auto Design ticked Const.type Composite

Gravity-only ticked

Accept Defaults

Rolled Beam Simple

Connections Grade

355

Un-check Auto select

Set Transverse to None

Restraints Connectors Studs - Strength Connectors - Layout

Accept defaults Listed

Stud Connector Standard Layout

Studs 19mm 100mm Height

E distance = 50mm

Un-check Auto Layout Set One Per Trough

(perpendicular) Repeat Distance of 300mm

(Parallel)

Accept all the other defaults in the attribute which is not listed above The General Page

The Design Options

The Reinforcement Option – Uncheck Auto-select and choose None

Studs Layout Option

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Note: The “e distance” is only applicable for re-entrant decks where the mean breadth of the concrete br = 2 * e for re-entrant profiles, where e = the distance to the nearer side of the rib but ≥ 25 mm. For trapezoidal profiles the mean breadth of the concrete rib br requires that the studs are placed centrally or in favourable positions. Group Spacing – uncheck Auto-layout

11.1.2 Applying the Attribute Set

Open a 2D-Roof view by double clicking on the “roof” level within the Project Pane.

Ensure that the composite attribute is set to default.

Use the selection tool and select Beams (or any other method you wish to apply the attribute)

Select the beams as listed in the 2D plan view, as shown below.

Then apply the defaulted attribute (composite) to the selected beams

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Ensure that you clear the selection set.

To confirm that the beams are now composite beams you can access View Options – Text tab and ensure that Beam Name is turned on. The beam reference will then be displayed (SB=Simple Beam, GB=General Beam, CB=Composite Beam). Note the beams have no section size against them because they are currently in auto-design mode.

Access View Options – Text tab and turn on Beam Name and Beam Attribute

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Composite Floor Design Validation Issues


11.2 Validation Issues

Validate the model

The output window returns problems with the model, Composite beam – “Floor construction not valid”.

Double click on the error message in the output window, and the beam in question will become highlighted.

Review the individual properties for the composite beam highlighted above.

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From the screenshot above, the construction type indicates a composite construction type, but the slab properties have been left blank (also highlighted in amber).

Fastrak will automatically calculate the effective width for the design of composite beams. When the situation occurs when you have an opening, or 2 different spanning slabs (slab 1, slab 3) Building designer will require further information from the user.

It is an engineering decision which slab is to be used in the design of this composite beam.

Select a slab

Select yes to re calculate effective widths.

Press ok and re validate the structure. Three errors will remain for the other problem beams

The same process will have to be repeated for the other three beams before the structure becomes valid BUT to make life easier we are going to rotate Slab 3 around to 0 degrees since this would be a mre logical decking layout for composite construction.

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Rotate slab 3 from 90 degrees to 0 degrees

Re-Validate the model

The model should validate without any errors or warning

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Composite Floor Design Composite Design Results


11.3 Composite Design Results

Re run the design process and take note of the output window.

As you can see above, for two of the beams, no section in the order file can satisfy the design criteria. In the Show/Alter State view you should see that 4 beams are failing

Exit out of show altered state and display the view below.

The 4 beams in question have all attained a section size but from the design status the spine and the edge beams next to the openings are failing. For the spine beams the section size returned is the largest in the order list.

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11.3.1 Failing Beams

Examine the design results for each beam

Results for the composite edge beam near the opening

In the beam above there is a fail in longitudinal shear. The beam is being considered an edge condition, but is located in an internal floor arrangement. Results for the composite spine beam

The Spine Beam has a failure in shear connection.

Critical Value Capacity Or Limit Notes

Longitudinal Shear 133.3 kN/m 139.7 kN/m Pass

Shear Connectors 15 35 Why Fail???

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Select the Connectors Tab

The degree of shear connectors is highlighted in amber (warning) and again shows the value 0.351 or 35.1% The minimum degree of shear connection required for partial shear connection = 0.486 or 48.6%. Therefore this is the reason the beam is failing.

This minimum for BS5950-3.1:1990 + A1:2010 Ductile is typically calculated from 1 – (355/Py)(0.8 – 0.03L) but not less than 40%. This minimum degree of interaction is material grade dependant.

There are different rules for higher ductility shear stud and significantly asymmetric beams.

Note the significant advantage in defining higher ductile studs for longer span beams. Minimum 0.4% apples until approx 20m span

Highlight the line by clicking “degree of Shear Connection”

Press the light bulb symbol

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The light bulb symbol allows the user to obtain an engineering tip on the reason for the failure. Taken From BS5950-Pt3.1:1990+A1:2010 reference clause Part 3-5.5

ENGINEERING TIP: Degree of shear connection

For spans up to 25m, the degree of shear connection should not be less than 0.4 at the position of maximum moment.

For spans > 25m, BS5950-3.1:1990+A1:2010 requires that the designer must demonstrate that the slip required

does not exceed the ductility of the shear connection to be adopted. Spans > 25m are beyond the scope of the software.

The number of connectors provided between the closer support and the critical position is Na.

For full shear connection, the number of connectors required between the closer support and the critical position is Np

The degree of shear connection is not simply Na/Np but is given by the ratio, Rq /min (Rc, Rs)

where

Rq = total resistance of Na shear connectors

Rc = total resistance of concrete

Rs = resistance of steel beam section

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Composite Floor Design Rectifying the Design Model


11.4 Rectifying the Design Model

11.4.1 Degree of Shear Connection

From the explanation above regarding the degree of shear connection, the amount of shear connectors placed between the point of maximum moment or any point load and back to the nearest support is not adequate.

We have options here, we could manually assign a reduced spacing or we could get the software to “auto-layout” to determine a spacing to satisfy this requirement. If you set as “auto-layout” this will provide a feel for the spacing required and then a manual spacing could be applied to increment to the nearest 25mm (for parallel arrangements), say to aid setting out. i.e. software determines 179.2mm it would be prudent to space at 175mm centres.

Edit the “Comp Gr 355 No-Reinforcement” attribute and on the connectors layout tab set to “auto-layout”. Click ok.

Select the two spine beams and re-apply the attribute

Then “Validate” and “Design” the model

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Interrogate the spine beam and you will see that the degree of interaction is satisfied with a group spacing of 198.1mm

Thus, we will make the decision to set the stud spacing at 200mm centres for the spine beams.

Edit the “Comp Gr 355 No-Reinforcement” attribute and on the connectors tab “uncheck” auto-layout and set the repeat distance for parallel direction to 200mm. Click ok.

Select the two spine beams and re-apply the attribute

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Then “Validate” and “Design” the model

11.4.2 Design Results after Adjustment of Studs

The four beams in question are still failing in the composite design.

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New results after alteration of the stud spacing

As can be seen from the design results the moment and the shear connectors are now passing the design criteria.

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11.4.3 Considering Longitudinal Shear

As can be seen above, an increase in the number of studs placed on the beam increases the shear area on the beam. This adjustment has increased the longitudinal shear resistance which has to be catered for. To cater for the increase of Longitudinal Shear force, Transverse Longitudinal Reinforcement will be applied to the beam. Fastrak Building Designer will automatically design the transverse reinforcement required on any composite beam. To apply automatic reinforcement design we will use the attributes. Already we have an attribute set “Composite Beam Gr 355 No-Reinforcement”. We can copy this attribute and re-create a new attribute with reinforcement.

Obtain the Beam Attributes List,

Ensure the “Composite Beam Gr 355 No-Reinforcement” is highlighted in the dialog box

Press Copy

A new attributes dialog will appear but will contain the exact data from the copied one.

Rename the Attribute Set and enter the information below.

General Design Alignment Type Support Size Reinforcement

Composite Beam - Auto Reinforcement

Auto Design Ticked Const.type Composite

Accept Defaults

Rolled Beam Simple Connections

Grade 355

Check Auto-Select Set Transverse High yield Steel, H

Restraints Connectors Studs Strength Connectors - Layout

Accept defaults Listed

Stud Connector Standard Layout

Studs 19mm 100mm Height E distance = 50mm

Un-check Auto Layout Set One Per Trough (perpendicular) Repeat Distance of 200mm (Parallel)

Select the reinforcement option, Set Transverse High yield Steel, H and set to check to Auto-Select

Also Check the option “Bar Spacing A Multiple of Stud Spacing”

By checking this option, the cross centres for the reinforcement will be placed in accordance with the arrangement of the studs on the beam. Since the transverse reinforcement is going to design automatically, we need to control the reinforcement bar sizes that building designer can pick from.

Select Connectors – Layout option

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Confirm that the repeat distance for parallel spans to 200mm

Select the Design tab and press Design Properties

In the Properties Area controls can be set for –

1. Size Constraints – Set Dimensional Criteria for the automatic designed beam 2. Section For Study – Set the order file and set elements in the order file to be considered for the design 3. Deflection – Set the deflection criteria for the element attribute 4. Natural Frequency (only applicable for composite beams) – Specify the natural design frequency 5. Reinforcement (only applicable for composite beams reinforcement being auto-designed) – Set the

diameter size for the reinforcement bars and the spacing that the auto design can pick from.

Select the reinforcement option and review the bar sizes the software is going to auto-design with and press ok

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Set this new attribute as the default and apply to the 4 beams in question

Validate and Design the model

All the beams should now be passing

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11.4.4 Copy Attributes Tool

An alternative to using “Apply Attribute” is to use the “Copy Attributes” tool. In this case you would edit a single beam until you were satisfied with the results then copy these attributes to the other members displaying warnings

Select the “Copy Attributes” tool; you will be prompted to ‘Select Source Beam’.

Select the beam whose attributes you wish to copy; you will be prompted to ‘Select Target Beam’

Each time you select a beam the attributes will be copied across.

De-select the tool once you have finished

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Composite Floor Design Instances when Composite Design Cannot be Achieved


11.5 Instances when Composite Design Cannot be Achieved

In certain conditions a composite beam design may not be possible due to the situation the beam is encountering. Problems that you may encounter:

1. Degree of Shear Connection (Requires 100% due to beam length) 2. Longitudinal Shear Problems 3. Effective width and slab assignment problems.

For example, 16m long span composite transfer beam, with the point of column transfer occurring very close to a support condition along with an opening along the beam. To change the properties of the beam from composite to simple follow the process below,

Right click on the following beam properties and press edit.

Under the design tab there is an option to treat the composite beam as “Non Composite”

Place a tick in the ‘treat as non composite’ box and notice the options change.

Press ok

Now Right Click on the same beam and select “Design Results”

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Composite Floor Design Instances when Composite Design Cannot be Achieved


The properties of the beam have been changed but design results can be obtained for the changes.

The results for the simple (non composite beam) are displayed on the screen.

As you can still see the reference name for the beam is still down as a “CB” composite beam but the results are as the beam properties of a non-composite beam.

11.5.1 Validity of Design Results

As can be seen above the design results are produced for the edited beam which have been compared to the original design forces. As soon as any changes are made to the model, the results tree will display question marks, “?”, showing that the model will

have to be “Validated” and “Designed” again.

Return the beam back to a composite beam and ensure that it passes the design.

221

Composite Floor Design Overview of Stud Layout Options


11.6 Overview of Stud Layout Options

There are three ways of specifying stud layouts for the automatic design of beams. 1. The engineer specifies the stud layout

In this case the engineer specifies the stud spacing and Fastrak will determine the most efficient section size available for the stud arrangement defined. This can be especially effective if the engineer wants to choose a simple stud layout common to a range of beams, i.e. all composite beams to have one stud per trough or studs at 300 mm c/crs. It should be acknowledged that setting limits to the stud spacing may prevent certain beams from finding a suitable section. However even this may be considered to be a benefit as this may be seen by the engineer as an indication that such beam should be designed as ‘non composite’ 2. Engineer selects an automatic number of uniform spacing of studs.

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In this circumstance the engineer is allowing the design process to select the number of studs required for the optimal design of any beam, provided that the spacing is consistent along the beam. This approach is commonly used on the basis that variation in stud spacing may be difficult to control on site. Note that in Fastrak Building Designer Version 10 the automatic design process will step from 1 to 2 to 3 studs in a group as long as this has been specified in the stud strength input dialogue. 3. Engineer selects an automatic number of non-uniformly spaced studs.

With these settings the engineer is allowing the design process to select the number of studs required for the optimal design of any beam, and allowing both the spacing and the number of studs to be calculated for the optimum design of the beam. To illustrate the detailed difference between the last two approaches please see the typical spine beam design below. Obsolete BS5950-3.1:1990 Example but similar principle applies. Example of uniform spacing auto design

For this beam an 838 x 292 x 194 UB has been selected with 35 pairs of shear studs. This give an interaction ratio of 52% at the centre of the beam, but a warning the minimum 40% interaction has not been achieved at the third point.

223



Using a standard spacing, to achieve 40% interaction at the third point you would need studs at about 220 mm spacing – that is 82 studs on the beam. With the extra studs you also need to increase the transverse shear provision to 10mm bars at 110 c/crs or 16 mm bars at 220 crs (to match the stud spacing). Example of non uniform spacing design

The same 838 x 292 x 194 UB section is selected, but the stud arrangement is 24,6,24 that is 24 studs between the support and the first secondary beam, 6 studs between the two secondary beams and 24 between the secondary beam and the end of the beam. That is 54 studs on the beam rather than the initial auto design of 70. Note that this beam still has the warning about the 40% interaction not being achieved at the first secondary beam. Resolving this with the stud spacing would require 28,6,28 with the same alteration of transverse shear reinforcement. At 62 studs that is 20 less than the simply ‘uniform’ stud layout or 25% less studs. You will notice that this design combines groups of two studs, with groups of one stud for maximum economy of design. Whether or not this approach is appropriate or worthwhile will be very much dependant upon the nature of the contract. There is no doubt that in the right circumstances it would be possible to make savings in the number of studs required with this alternative design.

The default setting for the automatic spacing of studs in an auto design will be uniform. Engineers who wish to consider non uniform spacing must specify this in the beam attributes.

225

Design Codes Overview of Stud Layout Options


12.0 Design Codes

227

Design Codes Design Codes - Introduction.


12.1 Design Codes - Introduction.

Fastrak Building Designer provides detailed structural design associated with the code of practice that has been selected by the user. This ‘CODE BASED DESIGN’ approach is important not just in the application of the detailed engineering design but also loading and load combinations. As an example the wind loading applied to a structure may differ significantly depending upon the selection of the BS (British Standard), EC (Eurocode) or ASCE (American Society of Civil Engineers) method. It is important therefore, that the user of Fastrak Building Designer understands which design code he is using within the software and has a detailed understand of the engineering design implications that using the specified code entails. Fastrak provides significant automation to the design process which is one of the key benefits to using the software.

12.1.1 Access to the various design codes.

Access to the different design codes is controlled by your licence agreement. Users in the UK with a current maintenance and update contract will normally be able to access BS and EC design codes, but not the US design code, unless this has been purchased separately.

12.1.2 To set the default design code.

When you first open Fastrak Building Designer a design code will be assumed. To change the default design code use the menu option : File -> Preferences (see below);

228

Design Codes Design Codes - Introduction.


12.1.3 To change the current design code (but leave the default design code unaffected)

To change the current design code use the menu option : Design -> Design Option (see below);

Things to know about changing the current design code

This facility can be particularly useful for users who are looking to understand the change from BS (British Standard) design to EC (Eurocode) design. However changing the design code can also fundamentally change the model. Material data, loading and combinations may need to be amended or deleted if you elect to change the design code. Users should be familiar with both the detail of the design code, and the implications of changing from BS to EC or Visa Versa. Detailed information on this is provided in the Fastrak Building Designer Eurocode training course. When a ‘new’ design code is selected the following warning appears.

In addition to this, material properties for steel and concrete (including the self weight of concrete) may be changed. The ability to change design codes, simply and quickly will provide a superb tool to help you carry out comparative designs to BS and EC, but as the model will be changed, you would be wise to ensure that you save a separate copy of the model before electing to change the design code.

229

Design Codes British Standard (BS) Based Design.


12.2 British Standard (BS) Based Design.

When designing to British Standard design codes, the software is working with; BS 5950-1:2000 (steel), BS 5950-3:1990 (composite) , BS 6399-2:1997 (loading including wind load) and a wide variety of industry publications including many provided by the Steel Construction Institute (SCI), for example, SCI 354 for Vibrations.

12.3 American Institute of Steel Construction (AISC) Based Design.

When designing to British Standard design codes, the software is working with; AISC 360 (steel) and (composite) , ASCE (loading including wind load) and a variety of industry publications including DG 11 (vibration of floors) and IBC (Seizmic loading).

12.4 Eurocode (EC) Based Design.

Eurocode based design was added to Fastrak Building Designer in 2009. When designing to Eurocode design codes, the software is working with; EC 1 (loading including wind loading), EC2 (concrete design), EC3 (steel design), EC 4 (composite design). EC 3 – steel design will be packaged in the UK by BSI as BS EN 1993. To be used each Eurocode needs the relevant national annex (NA) of the country where the building will be built. To be useful reference will need to make to a range of ‘non conflicting complimentary information’ known as NCCI. These documents provide a lot of the detail design guidance that was previously contained within the BS design codes, but is absent from the Eurocode based design codes. Fastrak provides a range of options with regard to the selection of the National Annex (see below) as well as a ‘Default’ Eurocode option that may be used in countries who have not specified a national annex. The differences between the UK national annex and the Irish national annex are more than superficial and users must take care to select the relevant national annex if appropriate.

Users should not mix national annexes.

Users would be advised not to mix design codes, although for purposes of comparison this may be allowed in the software, ie. If EC 3, EC 4 is selected as the design code, the wind loading should be calculated using EC 1 and NOT BS 6399.

USERS WHO ARE FAMILIAR WITH FASTRAK BUILDING DESIGN, BUT ARE NEW TO EUROCODES SHOULD CONSIDER ATTENDANCE ON OUR EUROCODE DESIGN COURSE ESSENTIAL TO AVOID WASTING SIGNIFICANT TIME OR MAKING ERRORS.

231

Creating an inclined roof structure Eurocode (EC) Based Design.


13.0 Creating an inclined roof structure

233

Creating an inclined roof structure Introduction


13.1 Introduction

In this section we will create the simple inclined roof as shown below to our completed Day 1 Training Model.

Key Steps

Create a new Construction level called “Apex level” at 17.0m (not a floor and hence no diaphragm action etc.)

Extend two columns up to the new Apex level

Create a new General Beam attribute and frame out the hip end roof steel work.

Create three planer roof items over the roof and set the appropriate span direction

Apply area loading to the roof items in appropriate load cases

Re-design the model to account for the new roof shape

234

Creating an inclined roof structure Creating the Apex Construction Level


13.2 Creating the Apex Construction Level

Access “Levels” from the Building File drop down menu and insert a new level called “Apex Level” at 17.0m.

Ensure that you remove the tick from Floor since this level is not a floor.

The other options are only applicable to floors

13.3 Extending the Columns to the new Apex level

Use “Select” and “Column” in 3D structure view to select the two columns as shown and then use Column Levels from the Building File drop down menu to extend the top of the column up to the new 17.0m construction level.

NB after depressing “Select” and “Column” always ensure clear selection is greyed out to ensure you reset what is already selected to in this mode.

13.4 Creating the new hip end steel roof beams.

Create a new “General Beam” attribute and set as the default

Note. Simple and Composite Beams are designed for shear and uni-axial bending under gravity loading only. General Beams are designed for shear, bi-axial bending (under and loading direction) and axial forces. Since axial forces will develop in the inclined rafters (and wish to design for the effect) we have set the rafters as general beams

235

Creating an inclined roof structure Creating Roof Items


Use “Create” and “Beam” and using the default attribute set place the rafters as shown below.

Note. Access the View Options, Floors tab and turn off Base, 1st

and 2nd

to make selection easier

In 3D click on the element you want to connect to. This ensures that only the node points displayed are selectable in the 3D view, thus making placement of rafters easier.

13.5 Creating Roof Items

Use “Create” and “Roof Item” to place planer roof items on the framed out steel structure above.

Roof Items can be placed by either clicking on the perimeter around the model as shown below…..

236

Creating an inclined roof structure Adjusting the Roof Item Span direction


…… or by double clicking on the elements to which the roof item is to be bounded.

Roof items should be created as large as possible so that if the Wind Modeller package is to be used the pressure zones can be calculated appropriately and user modifications are kept to a minimum.

13.6 Adjusting the Roof Item Span direction

1. A roof item span direction is always placed by default in the x direction of the model i.e. the roof item span direction is set at 0 degrees.

2. The view opposite shows a top down 3D structure view.

Select the two roof items highlighted using “Select” and “Roof Item” and in the properties box adjust the span direction to 45 degrees

237

Creating an inclined roof structure Adjusting the Roof Item Span direction


Clear the Selection using “Clear Selection” and then select the remaining roof item using “Select” and “Roof Item”

In the properties box set the span direction as either -45 or 135 degrees

The completed roof should look like this….

238

Creating an inclined roof structure Loading the Roof


13.7 Loading the Roof

The rafters can be loaded by either applying element loads directly to the rafters or by applying an area load to the roof items.

1. Area loading is achieved by ensuring the load case drop down box displays the load you wish to apply load into.

2. Then using “Create” and “Area load” click on a roof item.

3. A dialog box is displayed allowing you to assign either plan (display adjusted) or slope loading to the roof item.

4. Repeat for the other roof items

Try applying some area load to the model, resetting the columns and beams supporting the new roof structure back to auto design and re-designing the model.

REMEMBER TO ALWAYS CHECK THE NODAL DEFLECTIONS AND LOADING SUMMARY BEFORE REVIEWING INDIVIDUAL RESULTS.

239

Summary Loading the Roof


14.0 Summary

241

Summary Summary


14.1 Summary

This concludes the Fastrak Building Designer Day 1 course; the techniques learned today will enable you to build and design complex models however if you wish to use the software to its full potential it should be followed up by the Fastrak Building Designer Advanced Day 2 course. Topics covered on the advanced course include:

14.1.1 GENERAL MEMBERS AND CONTINUITY

Rigid bays and continuous designs

Understanding restraints, effective lengths and pattern loading

Comparison between 3D and 2D design models

Getting the analysis right: 3D Effects

14.1.2 ADVANCED 3D MODELLING

Import of 2D dxf drawings

DXF gridlines shadow or import - editing positions, sharing, grouping and modifying

Construction of roofs - sloping members and interconnection of elements

Applying cold rolled purlins to roofs

Creation and use of sub-structures.

14.1.3 FURTHER ANALYSIS AND DESIGN

Shear wall modelling and use of general beams and columns

Vibration of floors to P354

Truss member and truss wizard

Connections module

Connection design/modelling and disproportionate collapse

Designing for second-order effects

Discussion and overview of application of second order effects in Fastrak Building Designer

Building effective models in FTBD

Building Designer integration with 3D+ and Revit Structure

Wind module incorporating BREVe

CSC (UK) Ltd

Yeadon House, New Street Pudsey, Leeds LS28 8AQ United Kingdom

Tel: +44 (0) 113 239 3000Fax: +44 (0) 113 255 3917

[email protected] www.cscworld.com

© CSC (UK) Limited 2013. All Rights Reserved. Delivering:

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