lectures complete

Customer Training Material

L t 2Lecture 2

Mechanical Basics

Introduction to ANSYSIntroduction to ANSYSMechanical

L2-1ANSYS, Inc. Proprietary© 2010 ANSYS, Inc. All rights reserved.

Release 13.0November 2010

Introduction to ANSYS Mechanical

Customer Training MaterialChapter Overview• In this chapter, the basics of using Mechanical to perform analyses

will be covered, which include:A. The Mechanical Interface B. Introduction to the Mechanical Application WizardC. Basic Analysis ProcedureD. Applying Loads and SupportsE. Graphics Control and SelectionF. The Engineering Data applicationG. Workshop 2-1

• The capabilities described in this section are generally applicable to the ANSYS DesignSpace Entra licenses and above, unless noted.




Customer Training MaterialLaunching Mechanical• Recall that there are two ways of running Mechanical:– Configured from within ANSYS Workbench …

– … or from a supported CAD system… or from a supported CAD system




Customer Training MaterialA. The Mechanical Interface• The components of the user interface are shown below:

ToolbarsMenus

Graphics Window

Tree OutlineMechanical Application Wizard

Details View Message Window



Status Bar


Customer Training Material. . . Menus• The menus provide much of the functionality present in Mechanical.

The more commonly used menu items are covered below:– The title bar lists analysis type, product and active ANSYS license.– “View” controls various graphics options, legend and toolbars.– “Units” to change units on-the-fly.– “Tools > Options… ” to customize settings and options.– “Help > Mechanical Help” to access documentation.

Analysis Type Product License




Customer Training Material… Toolbars

• There are a number of toolbars to provide users quick access to functionality also found in the menus.

The toolbars can be repositioned anywhere on the top of the Mechanical– The toolbars can be repositioned anywhere on the top of the Mechanical window.

– The “Context” toolbar, as will be illustrated later, updates depending on what branch is active in the “Outline” tree.what branch is active in the Outline tree.

– Tooltips appear if the cursor is placed over the toolbar button.




Customer Training Material… Toolbars• The “Standard” toolbar is shown below:

Bring up Mechanical Wizard Annotations Comments

Solve Model

Capture Snapshot

Slice Planes

• The “Graphics” toolbar is used for selection and graphics manipulation:

Graphics ManipulationSelection ToolsSelect mode Viewports

– The left mouse button can be either in “selection” mode or “graphics manipulation” mode. The above toolbar buttons are grouped as “select entities” and “graphics manipulation” control.

– The graphics selection can be done using individual selection or box-



– The graphics selection can be done using individual selection or box-selection. This is controlled by the “Select Mode” icon.


Customer Training Material… Outline Tree• The Outline Tree provides an easy way of

organizing the model, materials, mesh, loads, and results for the analysis:– The “Model” branch contains the input

data required for the analysis. – The environment branch (in this case “Static

Structural”) contains the loads and supportsStructural”) contains the loads and supports relevant to the analysis discipline.

– The “Solution” branch contains resultobjects and solution informationobjects and solution information.

– Other branches (not covered here)are also available.




Customer Training Material… Outline Tree• The Outline Tree shows icons for each branch, along with a status

symbol. Examples of the status symbols are below:

– Checkmark indicates branch is fully defined/OK– Question mark indicates item has incomplete data (need input)– Lightning bolt indicates solving is requiredg g g– Exclamation mark means problem exists– “X” means that item is suppressed (will not be solved)– Transparent checkmark means body or part is hiddenp y p– Green lightning bolt indicates item is currently being evaluated– Minus sign means that mapped face meshing failed– Check mark with a slash indicates a meshed part/bodyp y– Red lightning bolt indicates a failed solution

Becoming familiar with the basic status symbols allows users to debug



Mechanical problems quickly.


Customer Training Material… Details View• The Details View contains data input and output fields. The contents

will change depending on branch selected.– White field: input data

• Data in white text field is editable– Gray (or Red) field: information

• Data in gray fields cannot be modified. – Yellow field: incomplete input data

• Data in yellow fields indicates missing information.




Customer Training Material… Graphics Window• The Graphics Window shows the geometry and results. Tabs allow

access to Print and Report Previews as well.




Customer Training Material… Worksheet View• Worksheet views are available for many objects in the tree (i.e.

geometry, connections, etc.).• Provides a list view of the data in the tree.

Activate Worksheet

Toggle between graphics and



graphics and worksheet


Customer Training MaterialB. The Mechanical Application Wizard• The Mechanical Wizard is an optional

component, a useful aid to remind users steps required to complete an analysis– The Mechanical Wizard provides a list of

required steps and the status of them.– Green checkmark indicates the item is complete.– Green “i” shows an informational item.– A grayed symbol shows that the step cannot be

performed yet.A red q estion mark means that there is an– A red question mark means that there is an incomplete item.

– An “x” means that the item is not performed yetA lightning bolt means that the item is ready to– A lightning bolt means that the item is ready to be solved or updated.

• The options on the Mechanical Wizard menu will change depending on the analysis type



will change depending on the analysis type chosen.


Customer Training Material. . . Mechanical Application Wizard• By selecting an item on the “Required Steps” checklist, a callout appears,

illustrating how that function is performed.– In the example below, “Verify Materials” was selected, and the callout shows the

user where this item can be changeduser where this item can be changed.




Customer Training Material… Mechanical Application Wizard• The Mechanical Wizard is handy for

users who do not use Mechanical every day.– Besides basic functionality, callouts

for more advanced items are also available as shown on right.




Customer Training MaterialC. Basic Analysis Procedure• The purpose of analysis is usually to determine the response of a

system based on some type of excitation or loading.• It is crucial to remember that a mathematical model is used:– CAD geometry is an idealization of the physical model– The mesh is a mathematical representation of the CAD model– The accuracy of answers is determined by various factors:y y

• How well the physical model is represented depends on the assumptions• Numerical accuracy is determined by the mesh density



CAD Model Finite Element Mesh


Customer Training Material… Basic Analysis Procedure• Every analysis involves four main steps:– Preliminary Decisions

• What type of analysis: Static, modal, etc.? Preliminary D i i• What to model: Part or Assembly?

• Which elements: Surface or Solid Bodies?– Preprocessing

Att h th d l t

Decisions

• Attach the model geometry• Define and assign material properties to parts• Mesh the geometry• Apply loads and supports

Preprocessing

Apply loads and supports• Request results

– Solve the Model– Postprocessing

Solution

p g• Review results• Check the validity of the solution

Postprocessing




Customer Training MaterialD. Applying Loads & Supports• Loads and supports are applied on geometric entities in two different ways:

– Pre-select geometry entity in Graphics Window, then select load or support from Context Toolbar

– Or, select load or support from Context Toolbar then select geometry entities in Graphics Window, then click on “Apply” in Details View.




Customer Training Material… Applying Loads & Supports• After assigning the load the user can enter additional data in the Details view,

if necessary.– Notice that in the Outline Tree the associated load’s branch symbol status will also

change to ‘completed’ (checkmark).g ( )




Customer Training Material… Applying Loads & Supports• For some structural loads direction is

needed:• If “Components” is chosen, enter X, Y, or Z

C t f l diComponents of loading• If “Vector” is chosen, select geometry and

enter magnitude of loading• Defaults can be set in “Tools > Options … p

> Mechanical: Miscellaneous > Load Orientation Type”

– The Global Coordinate System or user defined local coordinate systems can bedefined local coordinate systems can be referenced

• User-Defined Coordinate Systems will be discussed later




Customer Training Material… Applying Loads & Supports• Existing geometry can be referenced to

control direction:• In the “Details” view, select “Define By:

V t ”Vector”• Three types of existing geometry can be used

– Normal to planar face or along axis of cylindrical face

– Along straight edge or normal to cylindrical edge– Two vertices defining vector

• Click on “Direction” and select geometry used for vector orientation. Use the arrows in the Graphics window to toggle the direction.

• Click on “Apply” when finished.• Enter magnitude for loading in “Magnitude.”



Toggle arrow buttons to reverse load direction


Customer Training MaterialE. Graphics Control and Selection– The left mouse button is used to select geometric entities OR to

manipulate the graphics display

– User can select items (vertex, edge, surface, body) or manipulate the view (rotate, pan, zoom in/out, box zoom)S l t d b i l l t b l t– Select mode can be single-select or box-select

• In single-select mode, click-drag with left mouse button to “paint select” multiple items

• Use Ctrl-Left mouse button in single-select mode to select or unselect multiple g pentities– In box-select mode, click-drag from left to right selects entities fully enclosed in

bounding box– In box-select mode, click-drag from right to left selects any entity partially enclosed in , g g y y p y

bounding box




Customer Training Material… Graphics Control and Selection• In select mode the middle mouse provides several short cuts for graphics

manipulation– Click + drag middle mouse button = dynamic rotate– CTRL+ Middle mouse button = dynamic pan

S f– Shift + Middle mouse button = dynamic zoom– If present, the wheel can be used to zoom in/out– RMB + drag = box zoom– Click right mouse button once and select “Fit” to fit model in view or access

context menu optionscontext menu options




Customer Training Material… Graphics Control and Selection• Selection planes allow for users to easily select surfaces which are hidden

from view by other surfaces.– User selects a plane; if more planes lie directly underneath the cursor, selection

planes appear. Selection planes are color-coded with the same color as its parent part and are ordered by depth from the cursor.




Customer Training MaterialF. The Engineering Data Application• The Engineering Data application provides overall control for material

properties.– Engineering data is a part of every project.– Engineering data can be opened “stand alone” (as a precursor to starting

a project for example).

To edit the EngineeringTo open the Engineering Data To edit the Engineering Data in an existing project RMB > Edit or double click

p g gstandalone, add from the component systems in the toolbox (drag/drop or double click), then RMB > Edit or double click.




Customer Training Material. . . The Engineering Data Application• The Engineering Data application is displayed below. Individual

controls and components are described next.

Data Sources

Property Table

ToolboxIndividual Materials

Property Chart

Material Properties



Material Properties


Customer Training Material. . . The Engineering Data Application• The 2 icons in the toolbar control the basic

display of engineering data.• The first toggles a filter for the materials

shown in the toolbox:shown in the toolbox:– ON = only materials relevant to the current

analysis types are displayed.– OFF = all material properties are displayed.

• The second toggles the display of either theThe second toggles the display of either the project materials or the data source materials:– ON: data sources (libraries) are displayed.– OFF: materials for the current project are

displayeddisplayed.

Physics Filter for Toolbox Data Source/Project Display



Display


Customer Training Material. . . The Engineering Data Application• With data sources displayed the windows provide a cascading data presentation.• To view or modify materials one generally follows a work flow shown here:

Data Source > Material > PropertyData Source > Material > Property

Choose Data Source (Library)

Display Property

Choose Material

p y p yin tabular and graphical format

Choose Property




Customer Training Material. . . The Engineering Data Application

The Favorites field represents the materials which will be available in every

j

Check box allows library to be unlocked for editing. Libraries must be unlocked before materials can be modified

Data Sources

project. modified.

The list of available material libraries is displayed here. These may be ANSYSThese may be ANSYS supplied or user defined.

New user material libraries may be added by entering a name and a location.

Browse for existing libraries or choose new



by entering a name and a location.library location.


Customer Training Material. . . The Engineering Data Application• To add a material from an existing library to the current project click the

plus sign (+) next to that material.

Highlight the desired library

Click the “+” next to the desired material

Materials can be made available for all projects by designating them as “Favorites” using RMBby designating them as Favorites using RMB

IMPORTANT!: A material that is not displayed in the current engineering data will not be available in the current analysis.



= OFF


Customer Training Material. . . The Engineering Data Application• To create a new material toggle

to the project materials display.• Enter a name, and description if

d i d f th t i l

= OFF

desired, for the new material.

• From the ToolboxFrom the Toolbox double click or drag and drop the desired properties.

• Finally enter values for the properties.

• Note: properties can be added to existing materials using the



materials using the same technique.


Customer Training Material. . . The Engineering Data Application• Units menu in Engineering Data:– You may choose to display “Values as Defined”

or “Values in Project Units”.– “As Defined” units are controlled individually.

“Project Units” are taken from the current Units menu selection.




Customer Training MaterialG. Workshop 2-1 – Mechanical Basics

• Workshop 2.1 – Mechanical Basics• Goal:– Using the Stress Wizard, set up and solve a structural model for

stress, deflection and safety factor.




L t 3Lecture 3

General Preprocessingp g





Customer Training MaterialChapter Overview• In this chapter, using features without the use of the Wizards will be

covered• Topics:

A. GeometryB. ContactC. Coordinate SystemsyD. Named SelectionsE. Workshop 3-1, “Contact Control”

• The capabilities described in this section are generally applicable to the ANSYS DesignSpace Entra licenses and above and are noted in the lower-left hand tables




Customer Training Material… Introduction• The Outline Tree is the main way of setting up an analysis– The Context Toolbar, Details View, and Graphics Window update,

depending on which Outline Tree branch is selectedUse of the Outline Tree will be emphasized in this chapter– Use of the Outline Tree will be emphasized in this chapter

U f th O tli T iUse of the Outline Tree is the means by which users navigate through the Mechanical GUI.




Customer Training MaterialA. Geometry Branch• The Geometry branch lists the part(s)

that make up the model. • In Mechanical, there are three types of

bodies which can be analyzed:– Solid bodies are general 3D or 2D

volumes/areas/parts– Surface bodies are only areas– Line bodies are only curves– Each is explained next . . .




Customer Training Material… Types of Bodies• Solid bodies are geometrically and spatially 3D or 2D:

– 3D solids are meshed with higher-order tetrahedral or hexahedral solid elements with quadratic shape functions.2D solids are meshed with higher order triangle or quadrilateral solid elements– 2D solids are meshed with higher order triangle or quadrilateral solid elements with quadratic shape functions

• The “2D” switch must be set on the Project page prior to import• Geometry type cannot be changed from 2D to 3D (or vice versa) after import

– Each node has three translational degrees of freedom (DOF) for structural or one temperature DOF for thermal

Axisymmetric



3D Solids 2D Solidsy

cross section


Customer Training Material… Types of Bodies• Surface bodies are geometrically 2D but spatially 3D:

– Surface bodies represent structures which are thin in one dimension (through-thickness). Thickness is not modeled but supplied as an input value. Surface bodies are meshed with linear shell elements having six DOF (UX UY– Surface bodies are meshed with linear shell elements having six DOF (UX, UY, UZ, ROTX, ROTY, ROTZ).

• Line bodies are geometrically 1D but spatially 3D:– Line bodies represent structures which are thin in two dimensions. The cross-p

section is not modeled.– Line bodies are modeled with linear beam elements having six DOF (UX, UY, UZ,

ROTX, ROTY, ROTZ).



Line BodySurface Body


Customer Training Material… Multibody Parts• In general, bodies and parts are the same. In DesignModeler however,

multiple bodies may be grouped into multibody parts.• Multibody parts share common boundaries so nodes are shared at that

interface.interface.• No contact is needed in these situations.

• Example:

Common nodes are shared by adjacent bodies




Customer Training Material… Material Properties• To assign material properties to a body

highlight it and select from the available properties in the “Assignment” field :– The only materials appearing in the list

will be materials added using the “Engineering Data” application (see chapter 2)chapter 2).

• For surface bodies a thickness needs to be supplied as well.




Customer Training Material… Geometry Worksheet

• A summary of bodies and assigned materials is available.– Select “Geometry” branch and toggle the “Worksheet” icon.– Toggle between graphics or worksheet via tabs at bottom




Customer Training MaterialB. Contact• When multiple parts are present, a means of defining the relationship

between parts is needed.– Contact regions define how parts interact with each other.

With t t t t ld t ill t i t t ith h th• Without contact or spot welds, parts will not interact with each other:– In structural analyses, contact and spot welds prevent parts from penetrating

through each other and provide a means of load transfer between parts.– In thermal analyses, contact and spot welds allow for heat transfer across parts.y , p p– Multibody parts do not require contact or spot welds.

BALoad

Surface contact elements can be visualized as a “skin”



Surface contact elements can be visualized as a “skin” covering the regions where contact will occur.


Customer Training Material… Contact• When an assembly is imported contact

surfaces are automatically detected and created:– The proximity of surfaces is used to p y

detect contact. Tolerance for contact detection is available in the “Connections” branch details.

• Contact is also used for 2D geometry. g yContact “surfaces” are represented by edges.

• Certain license levels allow surface to edge, edge to edge and mixededge, edge to edge and mixed solid/surface contact.

• Note, automatic contact should always be checked and verified before



proceeding with an analysis.


Customer Training Material… Contact• Connections can be grouped for convenient contact management.• In the example shown, contact has been grouped relative to various

sub assemblies in the model.• Contact can be auto defined for each group via RMB.




Customer Training Material… Solid Body Contact– Contact elements provide the relationship between parts.– Each part maintains a separate mesh. This means that one small part will not

drive mesh density of the entire assembly and/or the user can make parts of interest have a finer mesh than other partsinterest have a finer mesh than other parts

Note the non-matching mesh at the interface between parts.pMix of hexahedral elements contacting tetrahedral elements is possible.




Customer Training Material… Solid Body Contact• When a contact region is highlighted in the connections branch, parts are made

translucent for easier viewing.– Selecting a contact region makes non participating bodies translucent.– Contact surfaces are color coded for easy identification.y




Customer Training Material… Solid Body Contact• “Go To” utilities allow a more detailed investigation of contact definitions:

– Corresponding bodies in tree– Bodies without contact– Parts without contact– Contact regions for selected bodies– Contacts common to selected bodies

– Contacts can be quickly renamed to match part namesq y p



RMB


Customer Training Material… Solid Body Contact• To manually define a contact pair insert a manual contact region and select

and apply “contact” and “target” surfaces.

RMB




Customer Training Material… Advanced Solid Body Contact• For ANSYS Professional licenses and above,

advanced contact options are available:– Auto detection dimension and slider

Pi b ll t l– Pinball control– Asymmetric contact, contact results tool and

additional formulations will be covered in a later chapter.

Details for Connections Details for Contact Regions



Details for Contact Regions


Customer Training Material… Advanced Solid Body Contact• The Pinball region represents a contact detection zone:

– Contact open status is determined by the pinball radius.• Outside pinball: far field• Inside pinball (not touching): near fieldp ( g)

– Closed status is either sliding or sticking.– The pinball radius may be entered so that bonded contact

is used in gaps.– Pinball radius is displayed as a sphere in the graphicsPinball radius is displayed as a sphere in the graphics

window.




Customer Training Material… Surface Body Contact

• Shell contact includes edge-to-face or edge-to-edge contact:– Shell contact is not turned on by default.y– User can turn on detection of face-to-edge or edge-to-edge

contact.– Priority can be set to prevent multiple contact regions in a

given regiongiven region.

Ed t S f Edge to Edge Edge to Surface



Edge to Surface Edge to Edge Edge to Surface


Customer Training Material. . . Mesh Connections• Mesh connections can be used to joint surface

bodies at the mesh that do not share topology.– Must be a multibody part (DM).– Can include gaps/penetration.– Can use automatic or manual creation.

For manual definition:

Master geometry can be faces or edges.

Slave geometry can only be edges



edges.


Customer Training Material… Spot Weld• Spot welds provide a means of connecting assemblies at discrete points:

– Spot weld is defined in the CAD software. Currently, only DesignModeler and Unigraphics define spot welds supported by Mechanical.

Spot weld pairs




Customer Training Material… Contact Worksheet• The “Worksheet” for the “Connections” branch provides a summary of

various contact and spot weld definitions:




Customer Training MaterialC. Coordinate Systems• The Coordinate Systems branch initially contains only the global Cartesian

system.• Coordinate systems can be used for mesh controls, point masses,

di ti l l d d ltdirectional loads, and results.• Local Coordinate Systems can be created or imported from some CAD systems

(see Mechanical documentation).




Customer Training Material… Coordinate Systems• Coordinate Systems (Cartesian or cylindrical) can be

defined by selecting “Coordinate System” icon from the Context toolbar.Th CS t lb b il bl ft CS i d fi d• The CS toolbar becomes available after CS is defined.

Delete

• Local coordinate systems are defined either by: S l ti t (A i ti C di t S t ) Th

Translate Rotate Flip Move Up/Down

– Selecting geometry (Associative Coordinate System). The coordinate system updates if the geometry’s location is updated (not during solution). Its translation and rotation are geometry dependent.

– Specifying coordinates (Non-Associative Coordinate System). The coordinate system will remain as originally defined i.e.: it is independent of geometry.




Customer Training Material… Coordinate Systems• Coordinate systems can be used from pull-down menus in the Details

view in various applications (examples below) :

Sizing w/ Sphere of

Directional ResultsPoint Masses

Sizing w/ Sphere of Influence Option

Directional Loads

Directional DisplacementsDirectional Displacements




Customer Training MaterialD. Named Selections• The Named Selection Toolbar provides functionality for grouping together

geometric entities:Manipulate Show/Hide Suppress/Unsuppress

Create Defined Names

– Named Selections allow users to group together vertices, edges, surfaces, or bodies.

– Named Selections can be used for defining mesh controls applying loads andNamed Selections can be used for defining mesh controls, applying loads and supports, etc.

– Provides an easy method to reselect groups that will be referenced often• Defining contact regions

S i lt• Scoping results• Etc.




Customer Training Material… Defining Named Selections• To create Selections using geometry selection:

– Select the vertices, edges, surfaces, or bodies of interest, then click on the “Create Selection Group” icon.Enter a name in the dialog box– Enter a name in the dialog box.

– The new group will appear in the Named Selection Toolbar as well as in the Outline Tree.

• Note:– Only one type of entity can be in a particular

Named Selection. For example, vertices and edges cannot exist in the same Named Selection.

– Named Selection groups can be imported fromsome CAD systems (see Chapter 10).




Customer Training Material… Defining Named Selections• Selections can be created employing various criteria using the

Worksheet method.• Add, remove, filter, etc. to “stack” criteria for complex selections.• Each selection is generated to complete the operation.




Customer Training Material… Defining Named Selections• Example, select a vertex at x,y,z = 97.7, 33, 0:• Using three operations (add, filter, remove),

allows a single vertex selection.

Results in 4 vertices selected

Results in 2 vertices selected

Results in 1 vertex selected




Customer Training Material… Using Named Selections• In many detail window fields Named Selections can be referenced

directly:• Example (pressure load):

“ f “G S “– In the Details view, change “Method” from “Geometry Selection” to “Named Selection”

– Select the “Named Selection” from the pull-down menu• Mechanical will filter non-applicable types of Named Selections. pp yp




Customer Training Material… Using Named Selections• Named Selections can be used in other situations where geometry must

be picked:– Select “Geometry” from the Details view to enter picking mode

T l th N d S l ti t l t f th T lb– Toggle the Named Selection to select from the Toolbar– Select the applicable choice:

• “Select Items in Group”, “Add to Current Selection”, “Remove from Current Selection” – Then, click on “Apply” in the Details view, pp y

12

3




Customer Training MaterialE. Workshop 3.1 – Contact Control

• Workshop 3.1 – Contact Control• Goal:– Investigate several types of contact behavior.




L t 4Lecture 4

Meshing in Mechanicalg





Customer Training MaterialChapter Overview• In this chapter controlling meshing operations is described.• Topics:

A. Global Meshing ControlsgB. Local Meshing ControlsC. Meshing TroubleshootingD. Virtual Topologyp gyE. Workshop 4-1, “Meshing Control”

• The capabilities described in this section are generally applicable to the ANSYS DesignSpace Entra licenses and above and are noted in the lower-left hand tablesthe lower left hand tables




Customer Training MaterialMeshing in Mechanical• The nodes and elements representing the geometry model make up the

mesh:– A “default” mesh is automatically generated during initiation of the solution.

Th “ t ” th h i t l i t if h t l– The user can “generate” the mesh prior to solving to verify mesh control settings.

– A finer mesh produces more precise answers but also increases CPU time and memory requirements.




Customer Training MaterialA. Global Meshing Controls• Physics Based Meshing allows the user to specify

the mesh based on the physics to be solved. Choosing the physics type will set controls such as:as:– Solid element mid-side nodes– Element shape checking– TransitioningTransitioning

• Physics preferences can be:– Mechanical– Electromagneticsg– CFD– Explicit

• Note: Some mesh controls are intended for non-Mechanical applications (CFD, EMAG, etc). Only mechanical mesh controls are discussed in this course



course.


Customer Training Material… Global Meshing Controls• Basic meshing controls are available under the “Defaults” group in the

“Mesh” branch– The user has control with a single slider bar

• “Relevance” setting between –100 and +100g

- Relevance = coarse mesh

+ Relevance = fine mesh




Customer Training Material… Global Meshing Controls

• Sizing Section: – The controls in this group set the basic

size defaults for the initial mesh. Local controls (described later), can be used to override these values in specific regions of the model.Th tti th “U Ad d– These settings assume the “Use Advanced Size Function” is set to “Off”.

• Relevance Center: sets the mid point of the “Relevance” slider control.Element Size: defines element size used for the entire model• Element Size: defines element size used for the entire model.

• Initial Size seed: Initial mesh size is based either on the entire assembly or on each individual part.

• Smoothing: Attempts to improve element quality by moving nodes. Number of smoothing iterations can be controlled (Lo Medi m High)smoothing iterations can be controlled (Low, Medium, High).

• Transition: Controls the rate at which adjacent elements will grow (Slow, Fast)




Customer Training Material… Global Meshing Controls• Advanced Size Functions: 4 settings to control basic mesh sizing.– Curvature: The curvature size function examines curvature on edges and

faces and sets element sizes so as not to violate the maximum size or the t l ( t ti ll t d d fi d b th )curvature angle (automatically computed or defined by the user).

– Proximity: The proximity size function allows you to specify the minimum number of element layers created in regions that constitute “gaps” in the model (features).Fixed: The fixed size function does not– Fixed: The fixed size function does not refine the mesh based on curvature or proximity. Rather, you specify minimum and maximum sizes and gradation is provided between sizes based on a specified growth rate.

– Note: users may accept default settings for these options or specify their own



for these options or specify their own (described next).


Customer Training Material… Global Meshing Controls• Curvature settings:– Normal angle: the maximum allowable angle that one element edge is allowed

to span (default based on relevance and span angle center settings).– Min Size: the minimum element edge size that the mesher will create.– Max Face Size: Maximum size the surface mesher will allow.– Max Size: Maximum size the volume mesher will allow.– Growth Rate: Specifies the increase in element size for each succeeding layer

progressing from an edge. A value of 1.2 represents a 20% increase. Settings from 1 to 5 with a default determined by relevance and transition settings.



Curvature = 20 deg. Curvature = 75 deg.


Customer Training Material… Global Meshing Controls• Proximity Settings:– Proximity Accuracy: Set between 0 and 1 (0.5=default). Controls the search

range used with the max size and cells across gap settings. A setting of 0 is f t tti f 1 i tfaster, a setting of 1 is more accurate.

– Num Cells Across Gap: specifies the number of element layers to be generated in the gap sections (i.e. between features).



Num Cells = 2 Num Cells = 5


Customer Training Material… Global Meshing Controls• Shape Checking:– Standard Mechanical – linear stress, modal

and thermal analyses.– Aggressive Mechanical – large gg g

deformations and material nonlinearities.• Element Midside Nodes:– Program Controlled (default), Dropped or

Kept (see below).Kept (see below).• Number of Retries: if poor quality elements

are detected the mesher will retry using a finer mesh.

• Mesh Morphing: when enabled allows updated geometry to use a morphed mesh rather than remeshing (saves time). Topology must remain the same and large geometry changes cannot be morphed.

Element A Element B



Kept Dropped


Customer Training MaterialB. Local Meshing Controls• Local Mesh Controls can be applied to either a Geometry Selection or a

Named Selection. These are available only when the mesh branch is highlighted. Available controls include :

Method Control– Method Control– Sizing Control– Contact Sizing Control– Refinement Control– Mapped Face Meshing– Match Control– Inflation Control– Pinch Control– Gap Tool (EMAG only, not covered)




Customer Training Material… Local Meshing Controls : Method (continued)

• Method Control : Provides the user with options as to how solid bodies are meshed:

• Automatic (default): B d ill b t if ibl Oth i th– Body will be swept if possible. Otherwise, the “Patch Conforming” mesher under “Tetrahedrons” is used.

• Continued . . .





• Tetrahedrons: – An all Tetrahedron mesh is generated. – Patch Conforming:

• All face boundaries are respected when mesh is created.

– Patch Independent Meshing:• Faces and their boundaries may or may not be respected during meshing

operations.• The exception is when a boundary condition is applied to a surface, its

boundaries are respected.boundaries are respected.





• Hex Dominant : Creates a free hex dominant mesh. Useful for meshing bodies that cannot be swept.

• Recommended for meshing bodies with large interior g gvolumes.

• Not recommended for thin or highly complex shapes.• Free Face Mesh Type: determines the mesh shape

to be used to fill the body (Quad/Tri or All Quad).

Solid Model with Hex dominant mesh :mesh :

Tetrahedrons – 443 (9%)

Hexahedron – 2801(62%)

Wedge – 124 (2%)



Pyramid – 1107 (24%)



• Sweep : – Sweep-mesh (hex and possible wedge) elements.– Type : Number of Divisions or Element Size in the sweep direction.– Sweep Bias Type : Bias spacing in sweep directionSweep Bias Type : Bias spacing in sweep direction.– Src/Trg Selection : Manually select the start/end faces for sweeping or allow the

mesher to choose.– Automatic/Manual Thin Model – One hex or wedge through the thickness. Can

choose between Solid Shell (SOLSH190) element and a Solid element (Solid185)choose between Solid Shell (SOLSH190) element and a Solid element (Solid185). A solid shell element is useful for thin structures with a single element through the thickness (e.g. sheet metal).





• MultiZone Method:– A patch independent mesher that automatically decomposes solid

geometry to accomplish sweep meshing (like a user might slice a model f hi )for meshing).

• Mapped Mesh Type: controls the shapes used for fill regions.

• Free Mesh Type: if set, allows tet meshes in the fill regions. Can set to “not allowed” if all hex is desired.

Standard Free Mesh



MultiZone Mesh


Customer Training Material… Local Meshing Controls• Sizing:– “Element Size” specifies average element

edge length or number of divisions ( h i d d t l ti )(choices depend on geometry selection).

– “Soft” control may be overridden by other mesh controls. “Hard” may not.Mesh biasing is available– Mesh biasing is available.

• Sphere of Influence sizing, see next page.

Entity Element Size # of Elem. Division Sphere of InfluenceBodies x xFaces x xEdges x x xVertices x



Vertices x

Face Sizing Applied to a part.

Size controls available based on geometry entity


Customer Training Material… Local Mesh Controls• Sphere of Influence:

– Center is located using local coordinate system.– All scoped entities within the sphere are affected by size settings.

“Sphere of Influence” (shown in red) has been defined Elements lying in Scoped to 2 surfacesScoped to single vertexdefined. Elements lying in that sphere for that scoped entity will have a given average element size.

p




Customer Training Material… Local Mesh Controls• Contact Sizing: generates similar-sized elements on

contact faces for face/face or face/edge contact region.– “Element Size” or “Relevance” can be specified.

Ch “C t t Si i ” f th “M h C t l” d– Choose “Contact Sizing” from the “Mesh Control” menu and specify the contact region.

– Or drag and drop a Contact Region object onto the “Mesh” object.

In this example, the contact region between the two parts h C t t Si i Thas a Contact Sizing Type Relevance is specified. Note that the mesh is now consistent at the contact region.




Customer Training Material… Local Mesh Controls

• Element refinement divides existing mesh– An ‘initial’ mesh is created with global and local size controls first, then element

refinement is performed at the specified location(s).– Refinement range is 1 to 3 (minimum to maximum). Refinement splits the edges of

the elements in the ‘initial’ mesh in half. Refinement level controls the number of iterations this is performed.

For example shown, the left side has refinement level of 2 whereas the right side is left untouched with defaultside is left untouched with default mesh settings.




Customer Training Material… Local Mesh Controls• Mapped Face Meshing: generates structured meshes on

surfaces:– In example below, mapped face meshing on the

outer face provides a more uniform mesh patternouter face provides a more uniform mesh pattern.

• Mapped quad or tri mesh also available for surface bodies.• See next slide for advanced options . . . .




Customer Training Material… Local Mesh Controls• For some geometry mapping will fail if an obvious pattern is not recognized.• By specifying side, corner or end vertices a mapped face can be achieved.

Original mapping failed as indicated next to the

By setting side and end vertices the mapped mesh succeeds



mesh control. resulting in a uniform sweep.


Customer Training Material… Local Mesh Controls• Inflation Control: useful for adding layers of elements along specific

boundaries.

Note: Inflation is more often used in CFD and EMAG applications but may



pp ybe useful for capturing stress concentrations etc. in structural applications.


Customer Training Material… Local Mesh Controls• Pinch: allows the removal of small features by “pinching”

out small edges and vertices (only).– Master: geometry that retains the original geometry profile.

Sl t th t h t t d th t– Slave: geometry that changes to move toward the master.– Can be automatic (Mesh level) or local (add Pinch branch).

Note: a global pinch control can be set in the mesh branch details “Defeaturing”



gsection.


Customer Training MaterialC. Meshing Troubleshooting• Mesh Metrics: can be requested in the “statistics” section.– Select individual bars in the graph to view the elements graphically.

Note: each mesh metric is described in detail in the “Meshing User’s Guide” of the ANSYS documentation



the ANSYS documentation.


Customer Training Material. . . Meshing Troubleshooting• If the mesher is not able to generate satisfactory elements, an error message

will be returned:

– The problematic geometry will be highlighted on the screen, and a named selection group “Problematic Geometry” will be created, so the user may review the model.




Customer Training Material… Meshing Troubleshooting• Meshing failures can be caused by a number of things:– Inconsistent sizing controls specified on surfaces, which would result in

the creation of poorly-shaped elements– Difficult CAD geometry, such as small slivers or twisted surfaces– Stricter shape checking (“Aggressive” setting in Mesh branch)

• Some ways to avoid meshing failures:– Specify more reasonable sizing controls on geometry– Specify smaller sizing controls to allow the mesher to create better-

shaped elements– In the CAD system, use hidden line removal plots to see sliver or

unwanted geometry and remove them– Use virtual cells to combine sliver or very small surfaces

Thi ti ill b di d t– This option will be discussed next




Customer Training MaterialD. Virtual Topology• Virtual Topology: combines surfaces and edges for

meshing control:

“Vi t l T l ” b h i dd d t th “M d l”– “Virtual Topology” branch is added to the “Model” branch.

– A “Virtual Cell” is a group of adjacent surfaces that “acts” as a single surface.

– Interior lines of original surfaces will no longer be honored by meshing process.

– For other operations such as applying Loads and Supports, a virtual cell can be referenced as a singleSupports, a virtual cell can be referenced as a single entity.

– Virtual cells can be generated automatically via RMB:• The “Behavior” controls the aggressiveness of the “Merge

Face Edges?” setting for auto generationFace Edges? setting for auto generation.

• Example . . .




Customer Training Material… Virtual Topology Example• Consider the example below:

Virtual Cell




Customer Training Material… Virtual Topology Example• Keep in mind that the topology can change!– Example: a chamfer is added to the top surface in this virtual cell. The

interior lines are not recognized anymore.Element’s edge is shown as a solid line and the original chamfer and top surface is shown as a dotted blue line.

The chamfer representation is no

Original mesh

The chamfer representation is no longer present.

Mesh using virtual



Mesh using virtual topology


Customer Training Material. . . Virtual Topology• In addition to creating virtual faces, edges can be split to form virtual

edges to aid in various meshing operations.

• Virtual Split Edge at +: splits at the selection point along thethe selection point along the edge.

• Virtual Split Edge: requires a fractional entry indicating the position along the edge where the split will be located (e g 0 5the split will be located (e.g. 0.5 results in the line split in half).




Customer Training MaterialE. Workshop 4.1 – Mesh Control

• Workshop 4.1 – Mesh Control• Goal:

Use the various mesh controls to enhance– Use the various mesh controls to enhance the mesh for the solenoid model.




L t 5Lecture 5

Static Structural Analysisy





Customer Training MaterialChapter Overview• In this chapter, performing linear static structural analyses in

Mechanical will be covered:A. GeometryB. Assemblies and Contact TypesC. Analysis SettingsD. Environment, including Loads and SupportsE. Solving ModelsF. Results and Postprocessing

• The capabilities described in this section are generally applicable to ANSYS DesignSpace Entra licenses and above.– Some options discussed in this chapter may require more advanced

licenses, but these are noted accordingly.




Customer Training MaterialBasics of Linear Static Analysis• For a linear static structural analysis, the displacements {x} are solved

for in the matrix equation below:

[ ]{ } { }FKAssumptions:– [K] is constant

[ ]{ } { }FxK =

• Linear elastic material behavior is assumed• Small deflection theory is used• Some nonlinear boundary conditions may be included

– {F} is statically applied{F} is statically applied• No time-varying forces are considered• No inertial effects (mass, damping) are included

• It is important to remember these assumptions related to linear staticl i N li t ti d d i l d i l tanalysis. Nonlinear static and dynamic analyses are covered in later

chapters.




Customer Training MaterialA. Geometry• In structural analyses, all types of bodies supported by Mechanical

may be used.

• For surface bodies, thickness must be supplied in the “Details” view of the “Geometry” branch.

• The cross-section and orientation of line bodies are defined within DesignModeler and are imported into Mechanical automaticallyDesignModeler and are imported into Mechanical automatically.




Customer Training Material… Point Mass

• A Point Mass can be added to a model (Geometry branch) to simulate parts of the structure not explicitly modeled:– A point mass is associated with surface(s) only.( ) y– The location can be defined by either:

• (x, y, z) coordinates in any user-defined Coordinate System.• Selecting vertices/edges/surfaces to define location.

Point mass is affected by “Acceleration ” “Standard Earth Gravity ” and– Point mass is affected by Acceleration, Standard Earth Gravity, and “Rotational Velocity”. No other loads affect a point mass.

– The mass is ‘connected’ to selected surfacesassuming no stiffness between them.

– No rotational inertial terms are present.




Customer Training Material… Material Properties• Young’s Modulus and Poisson’s Ratio are required for linear static

structural analyses:– Material input is handled in the “Engineering Data” application.– Mass density is required if any inertial loads are present.– Thermal expansion coefficient is required if a uniform temperature load

is applied. – Thermal conductivity is NOT required for uniform temperature

conditions.– Stress Limits are needed if a Stress Tool result is present.

F ti P ti d d if F ti T l lt i t– Fatigue Properties are needed if Fatigue Tool result is present.• Requires Fatigue Module add-on license.




Customer Training MaterialB. Assemblies – Solid Body Contact• When importing assemblies of solid parts, contact regions are automatically

created between the solid bodies.– Contact allows non-matching meshes at boundaries between solid parts

T l t l d “C t t” b h ll th t if di t f– Tolerance controls under “Contact” branch allows the user to specify distance of auto contact detection via slider bar




Customer Training Material… Assemblies – Solid Body Contact• In Mechanical, the concept of contact and target surfaces are used for each

contact region:– One side of a contact region is referred to as a contact surface, the other side is

referred to as a target surfacereferred to as a target surface.– The contact surfaces are restricted from penetrating through the target surface.

• When one side is designated the contact and the other side the target, this is called asymmetric contact. If b th id d t b t t & t t thi i ll d t i t t• If both sides are made to be contact & target this is called symmetric contact.

• By default, Mechanical uses symmetric contact for solid assemblies.

• For ANSYS Professional licenses and above the user may change to

TC

above, the user may change to asymmetric contact, as desired.

Symmetric Asymmetric



Sy et cContact

Asymmetric Contact


Customer Training Material… Assemblies – Solid Body Contact• Five contact types are available:

Contact Type Iterations Normal Behavior (Separation) Tangential Behavior (Sliding)Bonded 1 No Gaps No SlidingNo Separation 1 No Gaps Sliding Allowed

Bonded and No Separation contact are linear and require

Frictionless Multiple Gaps Allowed Sliding AllowedRough Multiple Gaps Allowed No SlidingFrictional Multiple Gaps Allowed Sliding Allowed

– Bonded and No Separation contact are linear and require only 1 iteration.

– Frictionless, Rough and Frictional contact are nonlinear and require multiple iterations.

• Nonlinear contact types allow an “interface treatment” option:

• “Add Offset”: input zero or non zero value for initial• “Add Offset”: input zero or non-zero value for initial adjustment

• “Adjusted to Touch”: ANSYS closes any gap to a just touching position (ANSYS Professional and above)




Customer Training Material… Assemblies – Solid Body Contact• Interface treatment options:

TCC TC T

Add offset: contact surface is numerically offset a given amount i iti ti di ti

Adjusted to touch: offsets contact surface to provide initial contact

ith t t dl f t l



in positive or negative direction (offset can be ramped on).

with target regardless of actual gap/penetration.


Customer Training Material… Assemblies – Solid Body Contact• Advanced options (see chapter 3 for

additional details on the pinball region):– Pin Ball Region:

• Inside pinball = near-field contact• Outside pinball = far-field contact• Allows the solver to more efficiently

process contact calculationsprocess contact calculations.

• For ANSYS Professional licenses and above,For ANSYS Professional licenses and above, mixed assemblies of shells and solids are supported as well as more contact options.

In this case, the gap between the two parts is bigger than the pinball region, so no automatic gap closure will be performed.




Customer Training Material… Assemblies – Spot Weld• Spot welds provide a means of connecting shell assemblies at discrete

points:– Spotweld definition is done in the CAD software. Currently, only DesignModeler

and Unigraphics define supported spot weld definitionsand Unigraphics define supported spot weld definitions.




Customer Training MaterialC. Analysis Settings• The “Analysis Settings” details provide general

control over the solution process:• Step Controls:

– Manual and auto time stepping controls.– Specify the number of steps in an analysis and an

end “time” for each step.– “Time” is a tracking mechanism in static analyses g y

(discussed later).

• Solver Controls:– Two solvers available (default program

chosen):• Direct solver (Sparse solver in ANSYS).• Iterative solver (PCG solver in ANSYS).

W k i– Weak springs:• Mechanical tries to anticipate under-

constrained models.




Customer Training Material. . . Analysis Settings – Analysis Data Management• Analysis Data Management:

– Solver Files Directory is the location where analysis files will be stored if a project has not yet been saved.

– Future Analysis: indicates whether a down stream analysis (e.g. pre-stressed modal) will use the solution. This is set automatically when coupled analyses are configured in the project schematicproject schematic.

– Scratch Solver Files Directory: temporary directory used during solution.

– Save MAPDL db.D l t U d d Fil h t ll– Delete Unneeded Files: may choose to save all files for future use in Mechanical APDL.

– Solver Units: Active System or manual.– Solver Unit System: if the above setting is

“ l” h 1 f 8 ibl“manual”, you may choose 1 of 8 possible solver unit systems to insure consistency when data is shared with Mechanical APDL (does not affect results/load displays in the GUI)



GUI).


Customer Training Material. . . Analysis Settings – Step Controls• Step Controls:

– Multiple steps allow a series of static analyses to be set up and solved sequentially.For a static analysis the end time can be used as– For a static analysis, the end time can be used as a counter/tracker to identify the load steps and substeps.

– Results can be viewed step by step.– Load values for each step can be entered in the

“Tabular Data” section provided.The time and load value are displayed in the graphics windowgraphics window




Customer Training Material. . . Multiple Steps• A summary of all the different steps can be viewed by highlighting

“Analysis Type” and then selecting the “Worksheet” tab.




Customer Training Material. . . Multiple Steps• Results for each individual step can be viewed after the solution by

selecting the desired step and RMB >“Retrieve This Result”.

Select desired step and RMB to retrieve resultretrieve result




Customer Training MaterialD. Loads and Supports• Loads and supports are thought of in terms of the

degrees of freedom (DOF) available for the elements used. UX

UY

• In solids the DOF are x, y and z translations (for shells we add rotational DOF rotx, roty and rotz).

• Supports, regardless of actual names, are always

UZ

defined in terms of DOF.

• For example a “Frictionless Support” applied to the Z surface of the block shown would indicate that the Z degree of freedom is no longer free (all other DOF g g (are free).

Frictionless surface




Customer Training Material. . . Loads and Supports• Load types:– Inertial loads:

• These loads act on the entire system.• Density is required for mass calculations.• These are only loads which act on defined Point Masses.

– Structural Loads:F t ti t f th t• Forces or moments acting on parts of the system.

– Structural Supports:• Constraints that prevent movement on certain regions.

Thermal Loads:– Thermal Loads:• The thermal loads which result in a temperature field causing thermal

expansion/contraction in the model.




Customer Training Material… Directional Loads• Loads and supports having a direction

component can be defined in global or local coordinate systems:

In the Details view change “Define By” to– In the Details view, change “Define By” to “Components”. Then, select the appropriate CS from the pull-down menu.

Load Supports Coordinate SystemsAcceleration NoAcceleration NoStandard Earth Gravity YesRotational Velocity YesForce YesRemote Force Location of Origin OnlyB i L d YBearing Load YesMoment YesGiven Displacement Yes




Customer Training Material… Acceleration & Gravity• Acceleration:– Acts on entire model in length/time2 units.– Acceleration can be defined by Components or Vector.y p– Body will move in the opposite direction of the applied acceleration.

• Standard Earth Gravity: V l li d i id ith l t d it t– Value applied coincides with selected unit system.

– Standard Earth Gravity direction is defined along one of three global or local coordinate system axes.B d ill i h di i f h li d i– Body will move in the same direction of the applied gravity.

• Rotational velocity:– Entire model rotates about an axis at a given rate.– Define by vector or component method.– Input can be in radians per second (default) or RPM.




Customer Training Material… Forces and Pressures• Pressure loading:– Applied to surfaces, acts normal to the surface.– Positive value into surface, negative value acts out of surface.– Units of pressure are in force per area.

• Force loading:– Forces can be applied on vertices, edges, or surfaces.pp , g ,– The force will be evenly distributed on all entities. Units are

mass*length/time2.

– Force can be defined via vector or component methods.




Customer Training Material… Hydrostatic Pressure• Hydrostatic Pressure:– Applies a linearly varying load to a surface (solid or

shell) to mimic fluid force acting on the structure.Fluid may be contained or external– Fluid may be contained or external.

• User specifies:– Magnitude and direction of acceleration.– Fluid Density.

C di t t ti th f f f th fl id– Coordinate system representing the free surface of the fluid.– For Shells, a Top/Bottom face option is provided.



Internal External


Customer Training Material… Bearing Load• Bearing Load (force):

– Force component distributed on compressive side using projected area.

• Axial components are not allowed• Axial components are not allowed.• Use only one bearing load per cylindrical

surface. – If the cylindrical surface is split be sure to

l t b th h l f li d i l fselect both halves of cylindrical surface when applying this load.

– Bearing load can be defined via vector or component method.



Bearing Load Force Load


Customer Training Material… Moment Load• Moment Loading :

– For solid bodies moments can be applied on a surface only.– If multiple surfaces are selected, the moment load is evenly distributed.

V t t th d b l d i th i ht h d l– Vector or component method can be employed using the right hand rule.– For surface bodies a moment can be applied to a vertex, edge or surface.– Units of moment are in Force*length.




Customer Training Material… Remote Load• Remote Force Loading :– Applies an offset force on a surface or edge of a body.– The user supplies the origin of the force (geometry or coordinates).– Can be defined using vector or component method.– Applies an equivalent force and moment on the surface.

– Example: 10 inch beam with a 1 lbf remote force scoped to the end of the beam. Remote force is located 20 inches from the fixed support.

F=1 lbf

20” Moment Reaction



Moment Reaction


Customer Training Material. . . Bolt Pretension

• Bolt Pretension:– Applies a pretension load to a solid cylindrical section or beam using:

• Pretension load (force)• Pretension load (force)• OR• Adjustment (length)

– For body loading a local coordinate system is required (preload in zFor body loading a local coordinate system is required (preload in z direction).

– For sequenced loading additional options are available (see next page).




Customer Training Material. . . Bolt Pretension – Sequenced Simulation• The “Define By” field in the details view provides the

following options for sequence loading:– Load or Adjustment: as defined on previous page.– Lock : Fixes all displacements (load applied and held).Lock : Fixes all displacements (load applied and held).– Open : Leaves the pretension load “open” (no pretension).

4

3

2

1

3• Bolt Load Tips:

– 3D simulations only.– Cylindrical surfaces or bodies only.



– A refined mesh is recommended (at least 2 elements in axial direction).


Customer Training Material. . . Line Pressure• Line Pressure loading : – Applies a distributed force on one edge only for 3-D simulations, using

force density loading.– Units are in force/length.– Can be defined by :

• Magnitude and Vector• Magnitude and component direction (global or local coordinate systems)• Magnitude and tangential




Customer Training Material… Supports• Fixed Support :

– Constraints all degrees of freedom on vertex, edge, or surface

• Solid bodies: constrains x, y, and z• Surface and line bodies: constrains x, y, z, rotx, roty and

rotz• Given Displacement :

– Applies known displacement on vertex, edge, or surfacepp p g– Allows for imposed translational displacement in x, y,

and z (in user-defined Coordinate System)– Entering “0” means that the direction is constrained,

leaving the direction blank means the direction is free.g

• Elastic Support : – Allows faces/edges to deform according to a spring

behaviorbehavior.– Foundation stiffness is the pressure required to produce

unit normal deflection of the foundation




Customer Training Material… Supports• Frictionless Support:

– Applies constraints (fixes) in normal direction on surfaces.– For solid bodies, this support can be used to apply a ‘symmetry’ boundary

condition. – Examples . . . Fixed in radial

direction

Free translation in plane of support

Fixed translation out of plane of support Free in tangential

and axial



and axial directions


Customer Training Material… Supports• Cylindrical Support:– Provides individual control for axial, radial, or tangential constraints.– Applied on cylindrical surfaces.

Radial

Tangential

AxialExample . . .




Customer Training Material… Supports (Solid Bodies)• Compression Only Support :– Applies a constraint in the normal compressive

direction only.– Can be used on a cylindrical surface to model a

pin, bolt, etc..– Requires an iterative (nonlinear) solution.

Force

Compression OnlyForce




Customer Training Material… Supports (Line/Surface Bodies)• Simply Supported :– Can be applied on edge or vertex of surface or line bodies– Prevents all translations but all rotations are free

• Fixed Rotation :– Can be applied on surface, edge, or vertex of surface or line bodies– Constrains rotations but translations are free

Translation fixed Translations free

Rotations free Rotations fixed



Simply Supported Edge Fixed Rotation Edge


Customer Training Material… Thermal Loading• Thermal condition :

– Applies a uniform temperature in a structural analysis.– Appears under “Loads” in structural analysis.– A reference temperature must be provided (see next slide).




Customer Training Material… Thermal Loading• A temperature differential can cause thermal expansion or

contraction in a structure:– Thermal strains (εth) are calculated as follows:

– α = thermal expansion coefficient (CTE material property).

( )refzth

yth

xth TT −=== αεεε

– Tref = reference temperature (thermal strains are zero).– T = applied temperature (see previous slide).– Reference temperature is defined in the environment branch (global)

or as a property of individual bodiesor as a property of individual bodies.




Customer Training Material… Solving the Model• To solve the model click on the “Solve” button on the Standard Toolbar.

– Two processors used if present (default).– To set the number use, “Tools > Solve Process Settings”.




Customer Training MaterialE. Workshop 5.1 – Linear Structural Analysis

• Workshop 5.1 – Linear Structural Analysis• Goal:– A 5 part assembly representing an impeller type pump is

analyzed with a 100N preload on the belt.




Customer Training MaterialF. Results and Postprocessing• Numerous structural results are available:– Directional and total deformation.– Components, principal, or invariants of stresses and strains.– Contact output.– Reaction forces.

• In Mechanical, results may be requested before or after solving.– If you solve a model then request results afterwards, click on the “Solve”

button , and the results will be retrieved. ,– A new solution is not required.




Customer Training Material… Plotting Results• Contour and vector plots are usually shown on the deformed geometry.• Use the Context Toolbar to change settings.




Customer Training Material… Deformation• The deformation of the model can be plotted:– Total deformation is a scalar quantity:

– The x, y, and z components of deformation can be requested under “Directional” in global or local coordinates

222zyxtotal UUUU ++=

requested under “Directional”, in global or local coordinates.– Vector plots of deformation are available (see below).




Customer Training Material… Stresses and Strains• Stresses and strains:

– Stresses and (elastic) strains have six components(x, y, z, xy, yz, xz) while thermal strains have three components (x, y, z)

– For stresses and strains, components can be requested under “Normal” (x, y, z) , p q ( , y, )and “Shear” (xy, yz, xz). For thermal strains, (x, y, z) components are under “Thermal.”

– Principal stresses are always arranged such that s1 > s2 > s3– Intensity is defined as the largest of the absolute valuesy g

• s1 - s2, s2 - s3 or s3 - s1




Customer Training Material… Stress Tools• Safety Factors (choose from 4 failure

theories):– Ductile Theories:

• Maximum Equivalent Stress• Maximum Shear Stress

– Brittle Theories:M h C l b St• Mohr-Coulomb Stress

• Maximum Tensile Stress– Within each stress tool safety factor, safety

margin and stress ratio can be plottedmargin and stress ratio can be plotted.




Customer Training Material… Contact Results• Contact results are requested via a “Contact

Tool” under the Solution branch.




Customer Training Material… Contact Results• Select the contact region(s) for the Contact Tool (2 methods):

1. Worksheet view (details): select contact regions from the list.• Contact, target or both sides can be selected.

2. Geometry: select contact regions on the graphics screen.




Customer Training MaterialUser Defined Results• In addition to the standard result items one can insert “user defined”

results.• These results can include mathematical expressions and can be

combinations of multiple result items.• Define in 2 ways:– Select “User Defined Result” from the solution context menu

– OR - From the Solution Worksheet highlight result > RMB > Create User Defined Result.




Customer Training Material. . . User Defined Results• Details allow an expression using various

basic math operations as well as square root, absolute value, exponent, etc..

• User defined results can be labeled with a user “Identifier”.

• Result legend contains identifier and expression.




Customer Training MaterialG. Workshop 5.2 – 2D Structural Analysis• Workshop 5.2 – 2D Structural Analysis• 2D structural analyses.• Shown here is the 2D axisymmetric model.

Pressure Cap Retaining Ring




L t 6Lecture 6

Vibration Analysisy





Customer Training MaterialChapter Overview• In this chapter, performing free vibration as well as pre-stressed

vibration analyses in Mechanical will be covered. In Mechanical, performing a free vibration analysis is similar to a linear static analysisanalysis.– It is assumed that the user has already covered Chapter 4 Linear Static

Structural Analysis prior to this section.• The following will be covered:g– Free Vibration Analysis Procedure– Free Vibration with Pre-Stress Analysis Procedure

• The capabilities described in this section are generally applicable to ANSYS DesignSpace Entra licenses and above.




Customer Training MaterialBasics of Free Vibration Analysis• For a free vibration analysis, the natural circular frequencies ωi and

mode shapes φi are calculated from:

[ ] [ ]( ){ }2

A i

[ ] [ ]( ){ } 02 =− ii MK φω• Assumptions:– [K] and [M] are constant:

• Linear elastic material behavior is assumedS ll d fl ti th i d d li iti i l d d• Small deflection theory is used, and no nonlinearities included

• [C] is not present, so damping is not included• {F} is not present, so no excitation of the structure is assumed• The structure can be constrained or unconstrainedThe structure can be constrained or unconstrained

– Mode shapes {φ} are relative values, not absolute




Customer Training MaterialA. Free Vibration Analysis Procedure

• The free vibration analysis procedure is very similar to performing a linear static analysis, so not all steps will be covered in detail. The steps in blue italics are specific to free vibration analyses.steps in blue italics are specific to free vibration analyses.– Attach Geometry– Assign Material Properties– Define Contact Regions (if applicable)Define Contact Regions (if applicable)– Define Mesh Controls (optional)– Define Analysis Type– Include Supports (if applicable)Include Supports (if applicable)– Request Modal Results– Set Modal Options– Solve the ModelSolve the Model– Review Results




Customer Training Material… Geometry and Point Mass

• Modal analysis supports any type of geometry:– Solid bodies, surface bodies and line bodies

• The Point Mass feature can be used:• The Point Mass adds mass only (no stiffness) in a free vibration analysis.• Point Masses will decrease the natural frequency in free vibration analyses.Point Masses will decrease the natural frequency in free vibration analyses.

• Material properties: Young’s Modulus, Poisson’s Ratio, and Density are required.a e equ ed




Customer Training Material… Contact Regions

• Contact regions are available in free vibration analyses. However, contact behavior will differ for the nonlinear contact types:

M d l A l iInitially Touching Inside Pinball Region Outside Pinball Region

Bonded Bonded Bonded Bonded FreeNo Separation No Separation No Separation No Separation FreeRough Rough Bonded Free Free

Contact Type Static Analysis Modal Analysis

• Contact free vibration analyses:R h d f i ti l

Frictionless Frictionless No Separation Free Free

– Rough and frictionless:• will internally behave as bonded or no separation• If a gap is present, the nonlinear contact behaviors will be free (i.e., as if no

contact is present).– Bonded and no separation contact status will depend on the pinball

region size.




Customer Training Material… Analysis Type• Select “Modal” from the Workbench toolbox to specify a modal

analysis system.• Within Mechanical Analysis Settings:– Specify the number of modes to find: 1 to 200 (default is 6).– Specify the frequency search range (defaults from 0Hz to 1e+08Hz).




Customer Training Material… Loads and Supports

• Structural and thermal loads are not available in free vibration.• Supports:– If no or partial supports are present, rigid-body modes can be

detected and evaluated (modes will be at or near 0 Hz). – The boundary conditions affect the mode shapes and frequencies ofThe boundary conditions affect the mode shapes and frequencies of

the part. Carefully consider how the model is constrained.– The compression only support is a nonlinear support and should

not be used in the analysisnot be used in the analysis.




Customer Training Material… Requesting Results

• Solve the model (no results need to be requested).• When complete, the solution branch will display a bar chart and table

listing frequencies and mode numbers.listing frequencies and mode numbers.

• Request specific mode shapes to be displayed by RMB (can select all frequencies if desired).q )

• This will insert the “Total Deformation” results for the requested mode shapes.




Customer Training Material… Reviewing Results• Mode shapes:

– Because there is no excitation applied to the structure, the mode shapes are relative values associated with free vibration.Th f i li t d i th D t il i f th lt b i i d– The frequency is listed in the Details view of the result being viewed.

– The animation toolbar from the timeline tab below the graphics window can be used to help visualize the mode shapes.




Customer Training MaterialB. Workshop 6.1 – Free Vibration

• Workshop 6.1 – Free Vibration Analysis• Goal:

– Investigate the vibration characteristics of motor cover design shown here manufactured from 18 gauge steel.




Customer Training MaterialC. Free Vibration with Pre-Stress

• In some cases, one may want to consider prestress effects when performing a free vibration analysis.

The stress state of a structure under constant (static) loads may affect– The stress state of a structure under constant (static) loads may affect its natural frequencies such as a guitar string being tuned.

[ ]{ } { }FK [ ] [ ]S→σ[ ]{ } { }FxK o =A linear static analysis is performed

[ ] [ ]So →σA stress stiffness matrix is calculated from the is performed structural analysis

( )[ ] [ ]( ){ } 02 =−+ ii MSK φωThe original free vibration equation is



g qmodified to include the [S] term


Customer Training Material… Procedure w/ Pre-Stress Effects• Setup a pre-stressed modal analysis by linking a static structural

system to a modal system (at the solution level) in the project schematic.

• Notice in the modal branch, the structural analysis result becomes an initial condition.



y


Customer Training Material… Example w/ Pre-Stress Effects• Consider a simple comparison of a thin plate fixed at one end– Two analyses will be run – free vibration and free vibration with pre-

stress effects – to compare the differences between the two.

Free Vibration Free Vibration with Pre-Stress




Customer Training Material… Example w/ Pre-Stress Effects• In this example, with the applied force, a tensile stress state is

produced which increases the natural frequencies.

Free Vibration Free Vibration with Pre-Stress



1st mode frequency: 83.587 Hz 1st mode frequency: 99.679 Hz


Customer Training MaterialD. Workshop 6.2 – Prestressed Modal• Workshop 6.2 – Prestressed Modal Analysis• Goal: simulate the modal response of the tension link (shown below)

in both a stressed and unstressed state.




L t 7Lecture 7

Thermal Analysisy





Customer Training MaterialChapter Overview• In this chapter, performing steady-state thermal analyses in Mechanical will

be covered:A.GeometryB Assemblies Solid Body ContactB.Assemblies – Solid Body ContactC.Heat LoadsD.Solution OptionsE. Results and PostprocessingF. Workshop 7.1

• The capabilities described in this section are generally applicable to ANSYS DesignSpace licenses and above, except for an ANSYS Structural license.DesignSpace licenses and above, except for an ANSYS Structural license.

• Note: advanced topics including thermal transient analyses are covered in the ANSYS Thermal Analysis training course.




Customer Training MaterialBasics of Steady-State Heat Transfer• For a steady-state (static) thermal analysis in Mechanical, the

temperatures {T} are solved for in the matrix below:

( )[ ]{ } ( ){ }TQTTK =• Assumptions:– No transient effects are considered in a steady-state analysis

( )[ ]{ } ( ){ }– [K] can be constant or a function of temperature– {Q} can be constant or a function of temperature




Customer Training MaterialBasics of Steady-State Heat Transfer

• Fourier’s Law provides the basis of the previous equation:• Heat flow within a solid (Fourier’s Law) is the basis of [K]• Heat flux, heat flow rate, and convection are treated as boundary conditions on y

the system {Q}• Convection is treated as a boundary condition although temperature-

dependent film coefficients are possible

• It is important to remember these assumptions related to performing• It is important to remember these assumptions related to performing thermal analyses in Mechanical.




Customer Training MaterialA. Geometry• In thermal analyses all body types are supported:– Solid, surface, and line bodies.

• Line bodies cross-section and orientation is defined within DesignModeler.• The “Point Mass” feature is not available in thermal analyses.

• Shell and line body assumptions:– Shells: no through-thickness temperature gradients. – Line bodies: no through thickness variation. Assumes a constant

temperature across the cross-section.• Temperature variation will still be considered along the line body




Customer Training Material… Material Properties

• The only required material property for steady state is thermal conductivity.

• Thermal Conductivity is input in the Engineering Data applicationpp

• Temperature-dependent th l d ti it ithermal conductivity is input as a table

If any temperature-dependent material properties exist, this will lt i li l ti



result in a nonlinear solution.


Customer Training MaterialB. Assemblies – Solid Body Contact• As with structural analyses, contact regions are automatically created to

enable heat transfer between parts of assemblies.




Customer Training Material… Assemblies – Contact Region

– If parts are initially in contact heat transfer can occur between them. – If parts are initially out of contact no heat transfer takes place (see pinball

explanation below).p )– Summary:

Heat Transfer Between Parts in Contact Region?Initially Touching Inside Pinball Region Outside Pinball Region

Bonded Yes Yes NoNo Separation Yes Yes NoRough Yes No NoFrictionless Yes No No

Contact Type Heat Transfer Between Parts in Contact Region?

– The pinball region determines when contact occurs and is automatically

Frictional Yes No No

The pinball region determines when contact occurs and is automatically defined and set to a relatively small value to accommodate small gaps in the model




Customer Training Material… Assemblies – Contact Region

• If the contact is bonded or no separation, then heat transfer will occur (solid green lines) when the surfaces are within the pinball radius.

Pinball Radius

In this figure on the right, the gap between the two parts is



bigger than the pinball region, so no heat transfer will occur between the parts


Customer Training Material… Assemblies – Thermal Conductance

• By default, perfect thermal contact conductance between parts is assumed, meaning no temperature drop occurs at the interface.

• Numerous conditions can contribute to less than perfect contact• Numerous conditions can contribute to less than perfect contact conductance:– surface flatness– surface finish– surface finish– oxides– entrapped fluids

contact pressureΔT

– contact pressure– surface temperature– use of conductive grease T

– . . . .

• Continued . . .

x




Customer Training Material… Assemblies – Thermal Conductance

– The amount of heat flow across a contact interface is defined by the contact heat flux q:

( )TTTCCq =

– where Tcontact is the temperature of a contact “node” and Ttarget is the temperature of the corresponding target “node”

( )contacttarget TTTCCq −⋅=

temperature of the corresponding target “node”. – By default, TCC is set to a relatively ‘high’ value based on the largest

material conductivity defined in the model KXX and the diagonal of the overall geometry bounding box ASMDIAG.o e a geo et y bou d g bo S G

ASMDIAGKXXTCC /000,10⋅=– This essentially provides ‘perfect’ conductance between parts.




Customer Training Material… Assemblies – Thermal Conductance• In ANSYS Professional licenses and above, the user may define a

finite thermal contact conductance (TCC) for Pure Penalty or Augmented Lagrange Formulations.– TCC is input for each contact region in the Details view.– If thermal contact resistance is known, invert this value and divide by the

contacting area to obtain TCC value.

Thermal contact conductance can be input which is the same as including thermal contact resistance at a contact interfaceresistance at a contact interface.




Customer Training Material… Assemblies – Spot Weld• Spot welds provide discreet heat transfer points:– Spotweld definition is done in the CAD software (currently only

DesignModeler and Unigraphics).

T2

T1




Customer Training MaterialC. Heat Loads

• Heat Flow:– A heat flow rate can be applied to a vertex, edge, or surface. The load is

distributed for multiple selections.– Heat flow has units of energy/time.

• Perfectly insulated (heat flow = 0):– Available to remove surfaces from previously applied boundary conditions.

• Heat Flux:– Heat flux can be applied to surfaces only (edges in 2D).– Heat flux has units of energy/time/area.

I t l H t G ti• Internal Heat Generation:– An internal heat generation rate can be applied to bodies only.– Heat generation has units of energy/time/volume.

A positive value for heat load will add energy to the system.




Customer Training Material… Thermal Boundary Conditions

Temperature, Convection and Radiation:• At least one type of thermal boundary condition must be present to prevent the

thermal equivalent of rigid body motionthermal equivalent of rigid body motion.• Given Temperature or Convection load should not be applied on surfaces that

already have another heat load or thermal boundary condition applied to it.• Perfect insulation will override thermal boundary conditions.

• Given Temperature:I t t ti d f b di– Imposes a temperature on vertices, edges, surfaces or bodies

– Temperature is the degree of freedom solved for




Customer Training Material… Thermal Boundary Conditions• Convection:– Applied to surfaces only (edges in 2D analyses).– Convection q is defined by a film coefficient h, the surface area A, and the q y , ,

difference in the surface temperature Tsurface & ambient temperature Tambient

( )bi tf TThAq −=

– “h” and “Tambient” are user input values.– The film coefficient h can be constant or temperature dependent

( )ambientsurface TThAq

The film coefficient h can be constant or temperature dependent




Customer Training Material… Thermal Boundary Conditions• Temperature-Dependent Convection:

– Select “Tabular (Temperature)” for the coefficient type.Enter coefficient vs temperature– Enter coefficient vs temperature tabular data.

– In the details, specify how temperature is to be handled for h(T).




Customer Training Material… Thermal Boundary Conditions• Several common convection correlations can be imported from a

sample library. New correlations can be stored in libraries.




Customer Training Material. . . Thermal Boundary Conditions• Radiation:– Applied to surfaces (edges in 2D analyses)

( )44 TTFAQ– Where:

• σ = Stefan-Boltzman constant• ε = Emissivity

( )44ambientsurfaceR TTFAQ −=σε

y• A = Area of radiating surface• F = Form factor

Correlations:– Correlations:– To ambient (form factor assumed to be 1) OR – Surface to surface (view factors calculated).Surface to surface (view factors calculated).

– Stefan Boltzman constant is set automatically based on the active working unit system




Customer Training MaterialD. Solution Options• Inserting the “Steady-State Thermal” from the

Workbench toolbox will set up a SS Thermal system in the project schematic.

• In Mechanical the “Analysis Settings” can be usedIn Mechanical the Analysis Settings can be used to set solution options for the thermal analysis.– Note, the same Analysis Data Management

options discussed in chapter 4 regarding static analyses are available hereanalyses are available here.




Customer Training Material… Solving the Model• To perform a thermal-stress solution link a structural analysis to

the thermal model at the Solution level.• An “imported load” branch is inserted in the Static Structural

branch along with any applied structural loads and supportsbranch along with any applied structural loads and supports.– Solve the Structural branch.




Customer Training MaterialE. Results and Postprocessing

• Various results are available for postprocessing:– Temperature– Heat FluxHeat Flux– “Reaction” Heat Flow Rate– User defined results

• In Mechanical, results are usually requested before solving, but they y g ycan be requested afterwards, too.– A new solution is not required for retrieving output of a solved model.




Customer Training Material… Temperature• Temperature:– Temperature is a scalar quantity and has no

direction associated with it.




Customer Training Material… Heat Flux• Heat flux contour or vector plots are available:

– Heat flux q is defined as

TKXXq ∇– “Total Heat Flux” and “Directional Heat Flux” can be

requested

TKXXq ∇⋅−=

• The magnitude & direction can be plotted as vectors by activating vector mode




Customer Training Material… Reaction Heat Flow Rate• Reaction heat flow rates are available for Given Temperature,

convection or radiation boundary conditions:– Reaction heat flow rate is requested by inserting a probe - OR– Alternately users can drag and drop a boundary condition onto the

Solution branch to retrieve the reaction.

Select from Probe menu

OR

Drag and drop boundary condition



boundary condition


Customer Training MaterialF. Workshop 7 – Steady State Thermal Analysis

• Workshop 7.1 – Steady State Thermal Analysis• Goal:– Analyze the pump housing shown below for its heat transfer

characteristics.




L t 8Lecture 8

Results and Postprocessing





Customer Training MaterialChapter Overview• In this chapter, aspects of reviewing results will be covered:

A. Viewing ResultsB. Scoping ResultsC. Exporting ResultsD. Coordinate Systems & Directional ResultsE. Solution CombinationsF. Stress SingularitiesG. Error EstimationH. Convergence

• The capabilities described in this section are applicable to all ANSYSThe capabilities described in this section are applicable to all ANSYS licenses, except when noted otherwise




Customer Training MaterialA. Viewing Results

• When selecting a results branch, the Context toolbar displays ways of viewing results:

Min/Max Probe

Displacement Scaling Display Method Contour Settings Outline Display

Vector Display Controls

• In addition, the “Timeline” also has an animation toolbar which lets the user set animation controls

DistributeDistribute Export



Play Pause Markers Frame Rate Control


Customer Training Material… Displacement Scaling• For structural analyses (static, modal, buckling),

the deformed shape can be changed:– By default, a scale factor “multiplies” actual displacements. – The user can change to true scale or undeformed displays.

True ScaleAutomatic Displacement Scaling




Customer Training MaterialLegend Controls• Right Clicking on the legend in the graphics area allows the user to

modify the legend controls.

Edit Value

Export/Import/Switch to a saved legend setting

Horizontal/Vertical legend

Display Date/Time

Display Max/Min label on the legendSwitch to Logarithmic Scale

Increase/Decrease Contour Bands

g

Switch to Scientific NotationNumber of Significant Digits

• Continued



Continued . . .


Customer Training Material… Legend ControlsThe legend bounds can be manipulated to show result distributions more clearly for contour plots.

Max/Min values are unchanged

Click and drag contour dividers (or type in) to specify contour ranges.

A non-uniform distribution of



contours can be used as well.


Customer Training Material… Manipulating the Legend

• Independent Bands allow neutral colors to represent regions of the model above or below the specified legend limits.

Legend Contour Range




Customer Training Material… Display Method• The “Geometry” button controls the contour display

method. Four choices are available:IsoSurfacesExterior

“Exterior” is the default display option and is most commonly used.

“IsoSurfaces” is useful to display regions with p y gthe same contour value.

“Capped IsoSurfaces” will remove regions of the model where the contour values are above (or below) a

Slice PlanesCapped IsoSurfaces

( )specified value.

“Slice Planes” allow a user to ‘cut’ through the model visually. A capped slice plane is also available, as shown



also available, as shown on the left.


Customer Training Material… Display Method• Capped IsoSurfaces are manipulated by an independent controller:– Icons allow isosurface cap to be top or bottom.– The striped areas of the legend show what values will not be displayed.p g p y– The cap threshold can be controlled via the slider or by typing the value

directly



Top Capped Isosurface Bottom Capped Isosurface


Customer Training Material… Contour Settings• The “Contours” button controls the way in which

contours are shown on the model

Contour BandsSmooth Contours

Solid FillIsolines




Customer Training Material… Outline Display• The “Edges” button allows the user show the

undeformed geometry or mesh

No Wireframe Show Undeformed Wireframe

Show Undeformed Model Show Elements




Customer Training MaterialSection Planes

• Section Planes can be added and edited in both the preprocessor as well as the post processor.– To add a section plane select the “Draw Section Plane”

icon, then click-drag with the left mouse.Selection planes can be turned on/off using the check– Selection planes can be turned on/off using the check box in the details view.

– Delete section planes using the delete icon.– Edit section planes by highlighting desired plane name

and using the ‘handle’ in the Graphics window.g p

Move a slice plane by dragging handle Sliced view of geometry in Preprocessor

Sliced view of model in Post Processor with results

Click on one side of bar to cap view




Customer Training MaterialProbe Tool• The Probe Tool allows you to scope a result object

to a location and make that result parametric.• The Probe Tool can be scoped to geometry, a local

coordinate system or using a remote point.• The orientation of the result item can be with respect

to global or local coordinate systems.




Customer Training Material. . . Probe Tool• Probe Tool example:– Local coordinate system defined as shown– Probe located at local CS– Stress results (all) requested

Local CS

Probe Location




Customer Training MaterialCharts and Tables• Combine results data from multiple steps (static or transient) into

charts and/or tables:– Select “New Chart and Table” icon.– From the details “Apply” the desired result(s).

• Use the CTRL key to select multiple results.– Select desired display items in details.




Customer Training MaterialAnimation Controls

• The animation toolbar allows user to play, pause, and stop animations• Note: animations are accessed via the “Timeline” at the bottom of the

graphics screen

Start/Stop/PauseControl resolution and speed

Distributed animation interpolates results while results sets animates only solution points.

Export video (avi) file



Note: pause feature available during playback


Customer Training Material… Alerts• Alerts are simple ways of check to see if a scalar result quantity

satisfies a criterion:– Highlight the particular result branch, RMB and insert an Alert.– In the Details view, specify the criterion.

– In the Outline tree, a green checkmark indicates that the criterion is satisfied. A red exclamation mark indicates that the criterion was not satisfied.




Customer Training Material… Vector Plots• Vector plots involve any result quantity with direction, such as

deformation, principal stresses/strains, and heat flux– Activate vectors for appropriate quantities using the vector graphics icon

– Once the vectors are visible their appearance can be modified using the vector display controls (see next slide for examples)

Vector Length Control Vector Density Control

Proportional Vectors Equal Length Vectors Grid AlignedElement Aligned Line Form Solid Form




Customer Training Material… Vector Plots• Examples

Proportional LengthSolid Form, Grid Aligned p g



Solid Form, Equal LengthEqual Length


Customer Training Material… Multiple Viewports• Multiple viewports can be used to display various images at the same

time (model or postprocessing data).– Useful to compare multiple results, such as results from different

environments or multiple mode shapes




Customer Training MaterialB. Scoping Results• Limiting results displays can be useful when postprocessing:– Scoping automatically scales the legend to results for selected regions.

• To scope contour results:p– Pre-select geometry then request the result of interest.– The non-selected geometry will be displayed as translucent.




Customer Training Material… Scoping Surface/Part Results• Some examples of scoping results on surfaces/parts:

Scoping results on a single part

Stress results on selected surfaces



Vector Principal Stresses on single part


Customer Training Material… Scoping Edge & Vertex Results• Results can be scoped to a single edge (or vertex):– Select edge(s) for results scoping.




Customer Training Material. . . Construction Geometry• Construction geometry consists of either a

path or surface.• Paths are defined using coordinate systems,

model edges or existing points.• Surfaces are located and oriented using

coordinate systems.




Customer Training Material. . . Scoping to a Path or Surface• Results may be mapped onto construction geometry in the details:

Path Plot Example

Surface Plot Example




Customer Training Material. . . Scoping to a Path• Path results may also be displayed in graphical form.• The X axis may be displayed as path location (S) or time (transient

analyses).




Customer Training Material. . . Linearized Stress• Using the path plot feature a linearized stress calculation can be

plotted (commonly used various structural codes such as ASME).




Customer Training MaterialC. Exporting Results

• To export Worksheet tab information:– Select the branch and click on the Worksheet tab.– Right-click the same branch and select “Export”.g p

• To export Contour Results:– Right-click on the result branch of interest and select “Export”.

• Tabular data from Mechanical can be exported to Excel:p– Select the cells to be exported.– Right click > Copy cell to copy all the data from the cells.– Paste into Excel.

Export Worksheet Export Results



pExport Tables


Customer Training Material… Exporting Results• To include node locations and vector directions in results exports,

change the “Include Node Location” option to “Yes” under “Tools menu > Options… > Mechanical: Export”




Customer Training MaterialD. Coordinate Systems

• Results containing directional components can be mapped to a local coordinate system:– Select from defined coordinate systems in the drop down list shown in y p

the detail window.– Direction Deformation, Normal/Shear Stress/Strain, and Directional Heat

Flux can use coordinate systems.




Customer Training Material… Coordinate Systems• For the model shown below, displaying results in the local cylindrical

system transforms stresses into that system.

Stresses in Global Y-Direction Stresses in Local Cylindrical Y-Direction




Customer Training MaterialE. Solution Combinations

• In the project schematic, duplicating an analysis cell below the Model branch (Setup, Solution or Result), allows the creation of Solution Combinations to quickly evaluate results combinations.

• Solution combinations are only valid for linear static structural analyses.• The supports must be the same between Environments (only the loading can

change).• ANSYS Professional license and above.




Customer Training Material. . . Solution Combinations

With the Model branch highlighted a “Solution C bi ti b h f th t tCombination can be chosen from the context menu.

A new branch is inserted where combined results b t d d t i dcan be requested and retrieved.

With the Solution Combination branch highlighted, the worksheet view allows multiple environments to be combined Note: a multiplication factor mayto be combined. Note: a multiplication factor may be included in combinations (see below).



Solution Combination = Coef 1 * Environment 1 + Coef 2 * Environment 2 + . . .


Customer Training Material… Solution CombinationsExample: a brake caliper is simulated in both standing and rolling configurations. After the 2 environments have solved a2 environments have solved a resulting combination shows the effect of both.



Solution Combination


Customer Training MaterialF. Stress Singularities• In most finite-element analyses as the mesh is refined one expects to

get mathematically more precise results.– Quantities directly solved for (degrees of freedom) such as

displacements and temperatures typically converge with little difficulty.– Derived quantities, such as stresses, strains, and heat flux, should also

converge as the mesh is refined but typically not as smoothly as DOF.I th d i d titi ill t th h i– In some cases these derived quantities will not converge as the mesh is refined and may even diverge.

– These cases are sometimes the result of some form of stress singularity.

ForceAreao ce

=σ As Area Zero ∞⇒σ




Customer Training Material… Stress Singularities• In a linear static structural analysis there are several situations which

may cause artificially high stresses:

Idealized Geometry Point Constraints Point Loads

• In the above situations, refining the mesh at the artificially high stress area will keep increasing the stresses.

⇒L8-36

ANSYS, Inc. Proprietary© 2010 ANSYS, Inc. All rights reserved.


∞⇒σ


Customer Training Material… Stress Singularities• The Remedy:– If the singularity is not in an area of interest one can usually scope

results to regions of interest.– If the singularity is in the area of interest there are several ways to obtain

more accurate stress results:• Model geometry with fillets or other details which do not cause geometric

discontinuitiesdiscontinuities.• Apply loads and/or constraints spread over areas rather than point locations

(see below).

Example



Point Loading Distributed Loading


Customer Training MaterialG. Error Estimation• You can insert an Error result based on stresses (structural), or heat

flux (thermal) to help identify regions of high error (see example next page).

• These regions show where the model could benefit from a more refined mesh in order to get a more accurate answer.

• Regions of high error also indicate where refinement will take place if convergence is used.




Customer Training Material. . . Error Estimation

• Error plot shows region of high element energy where mesh refinement may improve the quality of the result.improve the quality of the result.

• In the thin plate example the initial solution shows higher energy levels between the 2 holes.between the 2 holes.

• The refined mesh (bottom plot) shows a reduction in local error.

• Please note, error is a relative measurecomparing individual elements to one another The actual value of the energy isanother. The actual value of the energy is generally not significant.




Customer Training MaterialH. Convergence

• As the mesh is refined, typically the mathematical model becomes more accurate. However, there is computational cost associated with a finer mesha finer mesh.

• Obtaining an optimal mesh requires the following:– Having criteria to determine if a mesh is adequate.

I ti l t l h d d– Investing more elements only where needed.• Performing these tasks manually is cumbersome and inexact:– The user would have to manually refine the mesh, resolve, and compare

lt ith i l tiresults with previous solutions.• Mechanical has convergence controls to automate adaptive mesh

refinement to a user-specified level of accuracy.• Convergence controls cannot be used on all result items.




Customer Training Material… Convergence

• To use this feature select a result item RMB and insert “Convergence”:– Select max/min value for convergence and allowable change.– In the Solution branch details input the max number of refinement loops.




Customer Training Material… Convergence• After the solution is complete one can view the

results and the last mesh (symbols in the tree indicate success or failure to converge):

The mesh is refined only where needed (see below)– The mesh is refined only where needed (see below).– The Convergence branch shows the trend for each

refinement loop.



Convergence Divergence


Customer Training Material… Convergence & Scoping • A useful technique to avoid stress singularities when using

convergence is to scope results away from them.• If the singularity region is not of interest, one can scope results on

selected part(s) or surface(s) and add convergence controls to those results only:– Provides control on where to perform mesh refinement.– Ignores areas of artificially high stresses which are not of interest.

– Example:

Possible stress singularity



Region of interest


Customer Training Material… Convergence & Scoping Example

Convergence controls added to the entire model.

Geometric discontinuity causes a stress singularity causing divergence.

Solution becomes verySolution becomes very costly by including the stress singularity.

Convergence controls on scoped results allows adaptive refinement only in user-specified locations.

Provides more control over the mesh and the adaptive solution.



Accurate stresses realized in the region of interest.


Customer Training MaterialI. Workshop 8.1 – Advanced Results Processing

• Workshop 8.1 – Results Processing• Goal:

A l th h i l h b l d th f– Analyze the mechanical arm shown below and then use some of the advanced postprocessing features to review the stress and estimate the error associated with a default mesh.




L t 9Lecture 9

CAD & Parameters





Customer Training MaterialChapter Overview• In this chapter, interoperability with CAD software as well as

parameters will be discussed.A. CAD InteroperabilityB. Defining Parameters in WorkbenchC. Using the Parameter WorkspaceD. Updating CAD ParametersE. Workshop 9-1

• The capabilities described in this section are generally applicable to p g y ppall ANSYS licenses. However, some CAD functionality are specific to certain CAD software, so these will be designated accordingly.– Not all CAD software have the same features, so there are some

differences in CAD-related functionality which is supported in Mechanical.




Customer Training MaterialA. CAD Interoperability• Numerous Geometry Interfaces are available for commercial CAD

systems: – For the latest information on CAD geometry interfaces and supported

platforms see the ANSYS Workbench Mechanical documentation.• Geometry Interface licenses can be run in reader mode for all licenses.• Geometry Interfaces can be run in plug-in mode for the CAD software listed

d “A i ti ”under “Associative”.

• DesignModeler is the Workbench geometry application and supports all the functions and capabilities listed for commercial CAD systemsfunctions and capabilities listed for commercial CAD systems.

• Please note not all import capabilities described here are available with all• Please note, not all import capabilities described here are available with all CAD systems. Features depend on CAD capabilities and the support provided through the CAD vendor’s API.




Customer Training Material… CAD Interoperability• There are various items that can be

imported from supported CAD systems:– Geometry, Spot welds, Parameters,

Material properties, etc.• To access these import preferences use

the Geometry properties in the Project h tischematic.




Customer Training Material… Geometry Import

• Import solid, surface, or line bodies:– Assemblies with mixed solids and surfaces are

OK.Select desired geometry type to filter import– Select desired geometry type to filter import.

– Cannot import a part with mixed solids and surfaces.

• Use Associativity: – Allows updating CAD geometry in Mechanical

without redefining material properties, loads, supports, etc..

• Smart CAD Update: – only modified components of a CAD assembly are

updated.updated.

• Local Coordinate systems:– Allows local CS from CAD models to import with

geometry See current documentation for CAD



geometry. See current documentation for CAD system support.


Customer Training Material… Named Selections Import

• If “groups” are defined in the CAD package they can be imported as Named Selections:Selections:– “Groups” containing the specified prefix

in their name are imported in the Named Selection branch (default is “NS”)Selection branch (default is NS ).

– To import all groups leave the named selection key field blank.




Customer Training Material… Material Property Import• Material Properties: allow material

property import from supported CAD systems (see the current documentation f Cfor properties supported by various CAD vendors.

• Materials imported from CAD will appear p ppin the “Engineering Data” branch and will be assigned to individual parts.

• Note: – If the material type is changed in CAD,

this will be reflected in an update. p– if the property values of the material

change in CAD, this will not update. • This prevents overwriting user-defined

l i M h i l



values in Mechanical.


Customer Training Material… Parameter Import

• Parametric CAD dimensions can be imported into Mechanical:– When checked, CAD parameter names

containing the parameter key will be imported into Mechanical.To import all parameters leave the– To import all parameters leave the parameter key field blank.

– CAD parameters will appear in the Details view for the part.view for the part.

– Note: CAD parameters are “read only” atNote: CAD parameters are read only at this point.




Customer Training MaterialB. Defining Parameters in Workbench• Input and output parameters are defined in

Mechanical by toggling the parameter flag on/off.• Click in the square and a blue “P” will appear,

i di ti th t thi tit b i l t d

Example of input parameters

indicating that this quantity can now be manipulated as a parameter.

• Material properties are parameterized in the• Material properties are parameterized in the engineering data application.

Example of output parameters




Customer Training MaterialC. Using the Parameter Workspace

• Workbench Mechanical uses the Parameter Workspace to manage parametric data from analysis and geometry sources.

• Derived parameters and constants can be created and managed as p gwell.

Double click or “RMB > Edit” the “Parameter Set” to access parameters.




Customer Training Material. . . Using the Parameter Workspace• Parameter information is presented in a series of tables.– Outline: lists all input, output or derived parameters.– Property: lists information regarding the parameter highlighted in the

outline.

Table of DP

Table of Design Points: allows multiple

Outline

Table of DP

parameter configurations to be prepared before solving

Properties




Customer Training Material. . . Using the Parameter Workspace• Example using design points: A CAD

dimension has been promoted to a WB input parameter.

• The stress in a particular region of the model is promoted as an output parameter.

• The mass of the geometry has also been promoted to a parametric output.




Customer Training Material. . . Using the Parameter WorkspaceExample . . . • Opening the parameter

workspace, the parameters can be seen in the outline.seen in the outline.

• In the table of design points 3 g pnew values are added to the current CAD parameter value.

• From the top menu “Update



All Design Points” is selected.


Customer Training Material. . . Using the Parameter WorkspaceExample . . . • The progress of the updates is

reflected in the table.

• With updates complete various charts can be created to investigate the data.

St Fill tStress vs Fillet Radius




Customer Training Material… Using the Parameter Workspace• Additional processing in the parameter workspace:• Parameter Parallel Chart shows configuration of all parameters per DP

DP3

E h XY i t ti id h t f ll

DP2

Each XY intersection provides a snapshot of all parameters for a particular DP

Horizontal, colored lines represent design points. DP0

Vertical (Y) lines represent parameters

DP1



ep ese t pa a ete s(P1, P2, etc.).


Customer Training Material… Using the Parameter Workspace• By highlighting parameters, different chart configurations can be selected.

With P1 highlighted notice the chart options are with respect to this parameterare with respect to this parameter.

After selecting (double click) the desired chart, the outline can be configured for display.p y




Customer Training Material. . . Using the Parameter Workspace• As charts are created they are stored in

the outline window and can be retrieved by highlighting them.

• Using a RMB in various areas of the gchart users can “Edit Properties . . .” to control colors, styles, symbols, interpolation type, etc.

• Legend, line display, background, etc..




Customer Training MaterialD. Updating CAD Parameters (From CAD)• Update From CAD (Project Schematic):– After modifying the CAD geometry you will need to RMB and “Update

From CAD”. This will update the Mechanical geometry to match the CAD system.

– Doing an “Update”, causes new geometry to be remeshed in Mechanical.• Note, you can simply “Generate” the mesh in Mechanical as well.

• To allow bi-directional parametric pexchange the CAD parameters must be promoted.




Customer Training Material. . . Updating CAD Parameters (From Workbench)• With CAD parameters promoted, they can be managed in the Parameter

Set section of Workbench.• Values modified, description added, expression entered, etc..




Customer Training Material. . . Updating CAD Parameters (From Workbench)• If CAD Parameter Changes are made in WB:• Refresh Project: causes CAD and Mechanical geometry

to update but does not re-mesh the FE model.• Update Project: CAD and Mechanical models update• Update Project: CAD and Mechanical models update

and the FE model is re-meshed.

• Notes on geometry updates:Th it d f l d i t t– The magnitude of loads remain constant:

• Thus if pressure was applied on a surface and the surface area changes, the pressure value remains the same but the total force applied will change.

– The orientation of loads will not change:g• If a load direction is specified using existing geometry, the direction of the

load will not change if the geometry changes.




Customer Training MaterialE. Workshop 9.1 – Parameter Management

• Workshop 9.1 – Parameter Management• Goal:

Use the Workbench Parameter Workspace to setup multiple scenarios toUse the Workbench Parameter Workspace to setup multiple scenarios to explore structural responses in the bracket shown. Material thickness will be varied in the gusset with the bracket thickness held constant then the process will be reversed.



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