linear and nonlinear static and dynamic analysis...

SAP2000®

Linear and NonlinearStatic and Dynamic

Analysis and Designof

Three-Dimensional Structures

GETTING STARTED

COMPUTERS &

STRUCTURES

INC.

Computers and Structures, Inc.Berkeley, California, USA

Version 8.0June 2002

COPYRIGHT

The computer program SAP2000 and all associated documentation areproprietary and copyrighted products. Worldwide rights of ownershiprest with Computers and Structures, Inc. Unlicensed use of the programor reproduction of the documentation in any form, without prior writtenauthorization from Computers and Structures, Inc., is explicitly prohib-ited.

Further information and copies of this documentation may be obtainedfrom:

Computers and Structures, Inc.1995 University Avenue

Berkeley, California 94704 USA

tel: (510) 845-2177fax: (510) 845-4096

e-mail: [email protected]: www.csiberkeley.com

© Copyright Computers and Structures, Inc., 1978–2002.The CSI Logo is a registered trademark of Computers and Structures, Inc.SAP2000 is a registered trademark of Computers and Structures, Inc.Windows is a registered trademark of Microsoft CorporationAutoCAD is a registered trademark of Autodesk, Inc.FrameWorks Plus is a trademark of Intergraph Corporation

DISCLAIMER

CONSIDERABLE TIME, EFFORT AND EXPENSE HAVE GONEINTO THE DEVELOPMENT AND DOCUMENTATION OF SAP2000.THE PROGRAM HAS BEEN THOROUGHLY TESTED AND USED.IN USING THE PROGRAM, HOWEVER, THE USER ACCEPTS ANDUNDERSTANDS THAT NO WARRANTY IS EXPRESSED OR IM-PLIED BY THE DEVELOPERS OR THE DISTRIBUTORS ON THEACCURACY OR THE RELIABILITY OF THE PROGRAM.

THE USER MUST EXPLICITLY UNDERSTAND THE ASSUMP-TIONS OF THE PROGRAM AND MUST INDEPENDENTLY VERIFYTHE RESULTS.

ACKNOWLEDGMENT

Thanks are due to all of the numerous structural engineers, who over theyears have given valuable feedback that has contributed toward the en-hancement of this product to its current state.

Special recognition is due Dr. Edward L. Wilson, Professor Emeritus,University of California at Berkeley, who was responsible for the con-ception and development of the original SAP series of programs andwhose continued originality has produced many unique concepts thathave been implemented in this version.

Table of Contents

Chapter I Welcome to SAP2000 1

Chapter II Getting Started 3

Installing SAP2000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

If You are Upgrading... . . . . . . . . . . . . . . . . . . . . . . . . . . 3

About the Manuals . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Technical Support. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Help Us to Help You . . . . . . . . . . . . . . . . . . . . . . . . . 5Phone and Fax Support. . . . . . . . . . . . . . . . . . . . . . . . 5Online Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Chapter III The Structural Model 7

Units. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Objects and Elements . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Groups. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Coordinate Systems and Grids. . . . . . . . . . . . . . . . . . . . . . 10

Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Load Cases. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Functions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Analysis Cases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Combinations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Design Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Output and Display Definitions . . . . . . . . . . . . . . . . . . . . . 15

Learning More . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

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Chapter IV The Graphical User Interface 17

The SAP2000 Screen . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Main Window. . . . . . . . . . . . . . . . . . . . . . . . . . . . 17Menu Bar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18Toolbars. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18Display Windows . . . . . . . . . . . . . . . . . . . . . . . . . . 19Status Line . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Using the Mouse . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Viewing Options. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

2-D and 3-D Views . . . . . . . . . . . . . . . . . . . . . . . . . 21Perspective . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21Pan, Zoom, and 3-D Rotate . . . . . . . . . . . . . . . . . . . . . 22Limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22Element View Options . . . . . . . . . . . . . . . . . . . . . . . 22Other Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23Refreshing the Display Window . . . . . . . . . . . . . . . . . . 23

Basic Operations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

File Operations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Defining Named Entities . . . . . . . . . . . . . . . . . . . . . . . . 24

Drawing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Drawing Objects . . . . . . . . . . . . . . . . . . . . . . . . . . 26Snap Tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27Drawing Controls . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Selecting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Selecting Graphically . . . . . . . . . . . . . . . . . . . . . . . . 29Selecting by Feature . . . . . . . . . . . . . . . . . . . . . . . . 29

Editing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Assigning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Undo and Redo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Analyzing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Displaying . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Graphical Displays . . . . . . . . . . . . . . . . . . . . . . . . . 33Function Plots. . . . . . . . . . . . . . . . . . . . . . . . . . . . 34Tabular Displays . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Designing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Locking and Unlocking . . . . . . . . . . . . . . . . . . . . . . . . . 35

Entering Numerical Data . . . . . . . . . . . . . . . . . . . . . . . . 36

Setting Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Getting Help . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

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SAP2000 Getting Started

Chapter V Working with Data Tables 39

Classification of Tabular Data . . . . . . . . . . . . . . . . . . . . . . 39

Model Definition . . . . . . . . . . . . . . . . . . . . . . . . . . 39Analysis Results . . . . . . . . . . . . . . . . . . . . . . . . . . 40Design Results . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

Tables and Fields . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

Uses for Tabular Data . . . . . . . . . . . . . . . . . . . . . . . . . . 41

Formatted Tables for Presentation . . . . . . . . . . . . . . . . . 41Structured Database Tables . . . . . . . . . . . . . . . . . . . . . 42

Displaying Tabular Data. . . . . . . . . . . . . . . . . . . . . . . . . 42

Printing Tabular Data . . . . . . . . . . . . . . . . . . . . . . . . . . 44

Custom Report Writer . . . . . . . . . . . . . . . . . . . . . . . . . . 44

Format Control for Display and Printing . . . . . . . . . . . . . . . . 45

Interactive Table Editing . . . . . . . . . . . . . . . . . . . . . . . . 45

Exporting Tabular Data . . . . . . . . . . . . . . . . . . . . . . . . . 46

Importing Tabular Data . . . . . . . . . . . . . . . . . . . . . . . . . 47

Automatic Export During Save . . . . . . . . . . . . . . . . . . . . . 48

Export During Analysis . . . . . . . . . . . . . . . . . . . . . . . . . 48

Tabular Database File Formats . . . . . . . . . . . . . . . . . . . . . 49

Microsoft Access Database . . . . . . . . . . . . . . . . . . . . . 49Microsoft Excel Spreadsheet . . . . . . . . . . . . . . . . . . . . 49Plain Text File . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

More Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

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Table of Contents

iv


C h a p t e r I

Welcome to SAP2000

SAP2000 represents the most sophisticated and user-friendly release of the SAP se-ries of computer programs. When initially released in 1996, SAP2000 was the firstversion of SAP to be completely integrated within Microsoft Windows. It features apowerful graphical user interface unmatched in terms of ease-of-use and productiv-ity.

Creation and modification of the model, execution of the analysis, and checkingand optimization of the design are all done through this single interface. Graphicaldisplays of the results, including real-time display of time-history displacements,are easily produced. This program offers a quantum leap forward in the way modelsare created and modified, and in the way analysis and design are managed.

The analytical capabilities are just as powerful, representing the latest research innumerical techniques and solution algorithms. This release is available in three dif-ferent analytical versions that all share the same graphical user interface: SAP2000,SAP2000 PLUS and SAP2000 Nonlinear.

All of these programs feature sophisticated capabilities, such as fast equation solv-ers, force and displacement loading, non-prismatic frame elements, tension-onlybraces, highly accurate shell elements, Eigen and Ritz modal analysis, multiple co-ordinate systems for skewed geometry, many different constraint options, the abil-

1

ity to merge independently defined meshes, a fully-coupled 6-by-6 spring stiffness,and the option to combine or envelope multiple dynamic analyses in the same run.

The SAP2000 PLUS program adds unlimited capacity, bridge-analysis capabili-ties, a complete range of finite elements, and time-history analysis options. Groundmotion effects with multiple base excitations can be included. Harmonicsteady-state and power-spectral-density analyses are also available.

The SAP2000 Nonlinear version extends the PLUS capabilities by adding a nonlin-ear link element (gaps, hooks, isolators, dampers, and multi-linear plasticity), amulti-linear plastic hinge for use in frame elements, cable behavior, and geometricnonlinearity. Analysis capabilities include static nonlinear analysis for material andgeometric effects, pushover analysis, and staged construction; nonlinear time-his-tory analysis by modal superposition or direct integration; and buckling analysis.

All of the above programs feature powerful and completely integrated design forsteel, concrete, and aluminum, all available from within the same interface used tocreate and analyze the model. The design of steel and aluminum frame membersfeatures initial member sizing and iterative optimization. The design of concreteframe members includes the calculation of the amount of reinforcing steel required.Members can be grouped for design purposes, and a single mouse click on an ele-ment brings up the detailed design calculations. A wide variety of the latest nationaland international design codes are supported, and more are being added all the time.

All SAP2000 data, including model information, analysis results, and design re-sults, can be accessed using a tabular data structure. Tabular data can be edited anddisplayed in the interface, or exported to a Microsoft Access database file, aMicrosoft Excel spreadsheet file, or a simple text file. You can use exported data tocreate reports or to perform specialized calculations. This same tabular data can beimported into SAP2000, enabling you to generate or modify models outsideSAP2000. Import and export capabilities also exist for other popular drafting anddesign programs.

The SAP name has been synonymous with state-of-the-art analytical solutionssince the introduction of SAP, SOLIDSAP, and SAP IV thirty years ago, followedby its implementation on the PC with SAP80 and SAP90. To these sophisticatednumerical techniques, SAP2000 adds a tremendously easy and complete graphicaluser interface linked with powerful design capabilities, providing the structural en-gineer with an analysis and design program unequaled in efficiency and productiv-ity.

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C h a p t e r II

Getting Started

SAP2000 is a full-featured program which can be used for the simplest problems orthe most complex projects. This chapter will help you get started using the program.

Installing SAP2000Please follow the installation instructions provided in the separate installation doc-ument included in your SAP2000 Package, or ask your system administrator to in-stall the program and give you access to it.

If You are Upgrading...If you are upgrading from a previous version of SAP2000, you should be aware thatthere are a number of significant changes in the program, particularly:

• The model is defined in terms of Objects, which are automatically and inter-nally meshed into Elements during analysis.

• Loads Cases and Analysis Cases are now separate and distinct concepts.

• Text-based input has changed to be consistent with the new database capabili-ties.

Installing SAP2000 3

These changes significantly improve the capabilities of the program in a consistentand forward-looking way.

We recommend that you read the rest of this manual to familiarize yourself with thenew concepts. Please also see the topic “What’s New” in the Help facility withinthe program to learn more about the new and improved features in SAP2000.

About the ManualsThis manual and the other manuals in this volume are designed to help you quicklybecome productive with SAP2000. The next chapter gives an introduction to thebasic concepts of the graphical user interface and overall use of the program.

The second part of this volume, the SAP2000 Basic Analysis Reference manual,gives an introduction to the fundamental concepts underlying the structural modeland the analysis techniques used by SAP2000. It is recommended reading.

The third part of this volume, the SAP2000 Introductory Tutorial manual, is in-tended to provide first-time users with hands-on experience using the modeling,analysis and design features of SAP2000.

It is strongly recommended that you read this manual and work the tutorial beforeattempting a real project with SAP2000.

Additional information can be found in the on-line Help facility available withinthe SAP2000 graphical user interface, and in the other manuals supplied with theprogram. These manuals are available in Adobe Acrobat PDF format on theSAP2000 CD, and can also be accessed from within the program using the Helpmenu. They include:

• SAP2000 Analysis Reference, containing information about the advanced mod-eling and analysis features of the program.

• Various SAP2000 design manuals, containing detailed design features specificto supported design codes.

• SAP2000 Verification Manual, containing examples showing the capabilitiesand verifying the accuracy of the analytical features of the program.

Technical SupportFree technical support is available from Computers and Structures, Inc. (CSI) viaphone, fax, and e-mail for 90 days after the software is purchased. After 90 days,

4 If You are Upgrading...


technical support is available according to the terms of the Technical SupportAgreement, which you may purchase from CSI or your dealer. Please contact CSIor your dealer to inquire about a Technical Support Agreement.

If you have questions regarding use of the software, please:

• Consult the documentation and other printed information included with yourproduct

• Check the on-line Help facility in the program

If you cannot find a solution, then contact us as described below.

Help Us to Help You

Whenever you contact us with a technical-support question, please provide us withthe following information to help us help you:

• The program level (Standard, PLUS, or Nonlinear) and version number thatyou are using. This can be obtained from inside the program using the menucommand Help > About SAP2000.

• A description of your model, including a picture, if possible.

• A description of what happened and what you were doing when the problemoccurred.

• The exact wording of any error messages that appeared on your screen.

• A description of how you tried to solve the problem.

• The computer configuration (make and model, processor, operating system,hard disk size, and RAM size).

• Your name, your company’s name, and how we may contact you.

Phone and Fax Support

Standard phone and fax support is available in the United States, from CSI supportengineers, via a toll call between 8:30 A.M. and 5:00 P.M., Pacific time, Mondaythrough Friday, excluding holidays.

You may:

• Contact CSI’s office via phone at (510) 845-2177, or

• Send a fax with questions and information about your model (including a pic-ture, if possible) to CSI at (510) 845-4096.

Technical Support 5

Chapter II Getting Started

When you call, please be at your computer and have the program manuals at hand.

Online Support

Online support is available by:

• Sending an e-mail and your model file to [email protected]

• Visiting CSI’s web site at http://www.csiberkeley.com to read about frequentlyasked questions

If you send us e-mail, be sure to include all of the information requested above un-der subtopic “Help Us to Help You.”

6 Technical Support


C h a p t e r III

The Structural Model

SAP2000 analyzes and designs your structure using a model that you define in thegraphical user interface. The model consists primarily of the following types ofcomponents:

• Units

• Objects

• Groups

• Coordinate systems and grids

• Properties

• Load cases

• Functions

• Analysis cases

• Combinations

• Design settings

• Output and display definitions

The graphical user interface provides you with many powerful features to createyour model. You can even start with a preliminary model, then use the SAP2000design-optimization feature to refine your model with little effort.

7

The topics in this chapter describe these components in a little more detail.

UnitsSAP2000 works with four basics units: force, length, temperature, and time. Theprogram offers many different compatible sets of force, length and temperatureunits to choose from, such as “Kip, in, F” or “N, mm, C”. Time is always measuredin seconds.

An important distinction is made between mass and weight. Mass is used only forcalculating dynamic inertia and for loads due to ground acceleration. Weight is aforce that can be applied like any other force load. Be sure to use force units whenspecifying weight values, and mass units (force-sec2/length) when specifying massvalues.

When you start a new model, you will be asked to specify a set of units. These be-come the “base units” for the model. Although you may provide input data andview output data in any set of units, these values are always converted to and fromthe base units of the model.

Angular measure always uses the following units:

• Geometry, such as axis orientation, is always measured in degrees

• Rotational displacements are always measured in radians

• Frequency is always measured in cycles/second (Hz)

Objects and ElementsThe physical structural members in the model are represented by objects. Using theinterface, you “draw” the geometry of an object, then “assign” properties and loadsto the object to completely define the model of the physical member.

The following object types are available, listed in order of geometrical dimension:

• Point objects, of two types:

– Joint objects: These are automatically created at the corners or ends of allother types of objects below, and they can be explicitly added to modelsupports or other localized behavior.

– Grounded (one-joint) link objects: Used to model special support behav-ior such as isolators, dampers, gaps, multi-linear springs, and more.


8

• Line objects, of two types:

– Frame/cable objects: Used to model beams, columns, braces, trusses,and/or cable members.

– Connecting (two-joint) link objects: Used to model special member be-havior such as isolators, dampers, gaps, multi-linear springs, and more.Unlike frame/cable objects, connecting link objects can have zero length.

• Area objects: Used to model walls, floors, and other thin-walled members, aswell as two-dimensional solids (plane stress, plane strain, and axisymmetricsolids).

• Solid objects: Used to model three-dimensional solids.

As a general rule, the geometry of the object should correspond to that of the physi-cal member. This simplifies the visualization of the model and helps with the de-sign process.

If you have experience using traditional finite element programs, including earlierversions of SAP2000, you are probably used to meshing physical models intosmaller finite elements for analysis purposes. Object-based modeling largely elimi-nates the need for doing this.

For users who are new to finite-element modeling, the object-based concept shouldseem perfectly natural.

When you run an analysis, SAP2000 automatically converts your object-basedmodel into an element-based model that is used for analysis. This element-basedmodel is called the analysis model, and it consists of traditional finite elements andjoints (nodes). Results of the analysis are reported back on the object-based model.

You have control over how the meshing is performed, such as the degree of refine-ment, and how to handle the connections between intersecting objects. You alsohave the option to manually mesh the model, resulting in a one-to-one correspon-dence between objects and elements.

GroupsA group is a named collection of objects. It may contain any number of objects ofany number of types. Groups have many uses, including:

• Quick selection of objects for editing and assigning

• Incremental construction stages

Groups 9

Chapter III The Structural Model

• Defining section cuts across the model

• Grouping objects that are to share the same design

• Selective output

You may define as many groups as you need. Using groups is a powerful way tomanage larger models.

Coordinate Systems and GridsAll locations in the model are ultimately defined with respect to a single global co-ordinate system. This is a three-dimensional, right-handed, Cartesian (rectangular)coordinate system. The three axes, denoted X, Y, and Z, are mutually perpendicu-lar, and satisfy the right-hand rule.

SAP2000 always considers the +Z direction as upward. By default, gravity acts inthe –Z direction.

You may define additional coordinate systems to aid in developing and viewing themodel. These are defined with an origin and orientation measured with respect tothe global system.

For each coordinate system (the global and all additional systems), you can define athree-dimensional grid system consisting of intersecting “construction” lines usedfor locating objects in the model. Each grid may be of Cartesian (rectangular), cy-lindrical, or general type.

Drawing operations tend to “snap” to gridline intersections unless you turn this fea-ture off. This facilitates accurate construction of your model. When you move agrid line, you can specify whether or not points in the model should move with it.

Each object in the model (point, line, area, etc.) has its own local coordinate systemused to define properties, loads, and response for that object. The axes of each localcoordinate system are denoted 1, 2, and 3. Local coordinate systems do not have anassociated grid.

PropertiesProperties are “assigned” to each object to determine the structural behavior of thatobject in the model.

10 Groups


Some properties, such as material and section properties, are named entities thatmust be defined before assigning them to objects. For example, your model mayhave:

• A material property called CONCRETE

• A rectangular frame section property called RECT, and a circular section calledCIRC, both using material CONCRETE

• An area section property called SLAB that also uses material CONCRETE.

If you assign frame section property RECT to a frame object, any changes to thedefinition of section RECT or material CONCRETE will automatically apply tothat object. A named property has no effect on the model unless it is assigned to anobject.

Other properties, such as frame end releases or joint support conditions, are as-signed directly to objects. These properties can only be changed by making anotherassignment of that same property to the object; they are not named entities and theydo not exist independently of the objects.

Load CasesLoads represent actions upon the structure, such as force, pressure, support dis-placement, thermal effects, ground acceleration, and others. A spatial distributionof loads upon the structure is called a load case.

You can define as many named load cases as you like. Typically you would haveseparate load cases for dead load, live load, wind load, snow load, thermal load, andso on. Loads that need to vary independently, either for design purposes or becauseof how they are applied to the structure, should be defined as separate load cases.

After defining a load case name, you must assign specific load values to the objectsas part of that load case. The load values you assign to an object specify the type ofload (e.g., force, displacement, temperature), its magnitude, and direction (if appli-cable.) Different loads can be assigned to different objects as part of a single loadcase. Each object can be subjected to multiple load cases.

For example, suppose you have defined load cases named WIND, SNOW, andSUN15. For load case WIND, you might assign different windward and leewardpressure loads to vertical objects on opposite sides of the structure. For load caseSNOW, you might assign downward forces only to objects on the roof of the struc-ture. For load case SUN15, you might assign different temperature values to differ-

Load Cases 11


ent objects in the structure corresponding to the effects of sun on the structure at3:00 P.M. in the afternoon.

SAP2000 also has three built-in acceleration loads which represent unit groundtranslational acceleration in each of the global directions. These are automaticallyassigned to all objects in the structure that have mass.

In order to calculate any response of the structure due to the load cases, you mustdefine and run analysis cases (described below) which specify how the load casesare to be applied (e.g., statically, dynamically, etc.) and how the structure is to beanalyzed (e.g., linearly, nonlinearly, etc.) The same load case can be applied differ-ently in different analysis cases.

FunctionsYou define functions to describe how load varies as a function of period or time.They are only needed for certain types of analysis; they are not used for static analy-sis. A function is a series of digitized abscissa-ordinate data pairs.

There are two types of functions:

• Response-spectrum functions: Pseudo-spectral acceleration vs. period for usein response-spectrum analysis

• Time-history functions: Loading magnitude vs. time for use in time-historyanalysis.

You may define as many named functions as you need. They are not assigned to ob-jects, but are used in the definition of analysis cases.

Analysis CasesAn analysis case defines how loads are to be applied to the structure, and how thestructural response is to be calculated. There are many different types of analysiscases. Most broadly, analyses are classified as linear or nonlinear, depending uponhow the structure responds to the loading.

The results of linear analyses may be superposed, i.e., added together after analysis.The available types of linear analysis are:

• Static: The most common type of analysis. Loads are applied without dynami-cal effects.

12 Load Cases


• Modal Analysis: Calculation of dynamic modes of the structure byeigenvector or Ritz-vector method. Loads are not actually applied, althoughthey can be used to generate Ritz vectors.

• Response-spectrum Analysis: Statistical calculation of the response due toacceleration loads. Requires response-spectrum functions.

• Time-history Analysis: Time-varying loads are applied. Requires time-his-tory functions. The solution may be by modal superposition or direct integra-tion methods.

• Buckling Analysis: Calculation of buckling modes under the application ofloads.

• Moving Load Analysis: Calculation of the most severe response due to vehi-cle loads moving along lanes on the structure. Uses defined vehicle loads anddefined lanes rather than the load cases used by other analysis types.

The results of nonlinear analyses should not normally be superposed. Instead, allloads acting together on the structure should be combined directly within the analy-sis cases. Nonlinear analysis cases may be chained together to represent complexloading sequences. The available types of nonlinear analyses are:

• Nonlinear Static: Loads are applied without dynamical effects. May be usedfor pushover analysis and staged construction.

• Nonlinear Time-history Analysis: Time-varying loads are applied. Requirestime-history functions. The solution may be by modal superposition or directintegration methods.

You may define as many named analysis cases of any type that you wish. When youanalyze the model, you may select which cases are to be run. You may also selec-tively delete results for any analysis case.

Analysis results, when available, can be considered to be part of the model. Theyare needed in order to perform design.

CombinationsA SAP2000 combination, also called a “combo,” is a named combination of the re-sults from one or more analysis cases and/or other combinations. When a combina-tion is defined, it applies to the results for every object in the model.

There are four types of combinations:

Combinations 13


• Additive type: Results from the included analysis cases and/or combos areadded.

• Absolute type: The absolute values of the results from the included analysiscases and/or combos are added.

• SRSS type: The square root of the sum of the squares of the results from the in-cluded analysis cases and/or combos is computed.

• Envelope type: Results from the included analysis cases and/or combos are en-veloped to find the maximum and minimum values.

Except for the envelope type, combinations should usually be applied only to linearanalysis cases, since nonlinear results are not generally superposable.

Design is always based on combinations, not directly on analysis cases. You maycreate a combination that contains just a single analysis case. Each design algo-rithm creates it own default combinations. You may add your own for design orother purposes.

Design SettingsThe design features of the program can be used on frame/cable objects whose sec-tion properties use materials of concrete, steel, or aluminum. There are several set-tings you can make that affect the design of a particular model:

• The specific design code to be used for each type of material, e.g.,AISC-LRFD93 for steel, EUROCODE 2-1992 for concrete, and AA-ASD2000 for aluminum

• Preference settings of how these codes should be applied to your model

• Combinations for which the design should be checked

• Groups of objects that should share the same design

• For each object, optional “overwrite” values that specify coefficients and pa-rameters used in the design-code formulas that you wish to change from the de-fault values chosen by the program

For steel and aluminum design, the program can automatically select an optimumsection from a list you define. You can also manually change the section during thedesign process. As a result, each frame/cable object can have two different sectionproperties associated with it:

• An “analysis section” used in the previous analysis, and

14 Combinations


• A “design section” resulting from the current design.

The design section becomes the analysis section for the next analysis, and the itera-tive analysis and design cycle should be continued until the two sections becomethe same.

Design results for the design section, when available, as well as all of the settingsdescribed above, can be considered to be part of the model.

Output and Display DefinitionsThe definition of the SAP2000 model and the results of analysis and design can beviewed and saved in many different ways. These include:

• Two- and three-dimensional views of the model

• Tables of values in plain text, spreadsheet, or database format

• Formatted documents containing tables of values in rich text and HTML format

• Function plots of analysis results

• Design reports

• Export to other drafting and design programs

You may save named definitions of display views, sets of output tables, documentformats, and function plots as part of your model. Combined with the use of groups,this can significantly speed up the process of getting results while you are develop-ing your model.

Learning MoreEach SAP2000 model is like a living thing that grows and changes as you developit, run analyses, perform design, and review results. This chapter presented some ofthe basic features that make up a structural model, but to really understand themodel you must also learn how to work with it.

The next chapter describes how to use the SAP2000 interface to do just that. Basicconcepts and techniques will be presented. To put all this information together, werecommend that you read and perform the tutorial example given in the SAP2000Introductory Tutorial manual, included in this volume.

Output and Display Definitions 15


You can learn more about the details of using the graphical user interface by usingthe Help facility within the interface itself. Information about the SAP2000 modelis also available in the Help facility.

16 Learning More


C h a p t e r IV

The Graphical User Interface

The SAP2000 graphical user interface (GUI) is used to model, analyze, design, anddisplay the results for your structure. This chapter introduces you to some of the ba-sic concepts of the graphical user interface and sets the stage for the tutorial de-scribed later in this volume. More advanced concepts and features are described inthe on-line Help facility of the graphical user interface itself.

Please first read the previous chapter, “The Structural Model,” since all operationsdescribed in this chapter are used to work with a SAP2000 model.

The SAP2000 ScreenAfter starting the program, the SAP2000 graphical user interface appears on yourscreen and looks similar to the figure on the next page. The various parts of the in-terface are labeled in the figure and are described below.

Main Window

The main window contains the entire graphical user interface. This window may bemoved, resized, maximized, minimized, or closed using standard Windows opera-tions. The main title bar, at the top of the main window, gives the program name andthe name of the model file.

The SAP2000 Screen 17

Menu Bar

The menus on the Menu Bar contain almost all of the operations that you can per-form with SAP2000. These operations are called menu commands, or simply com-mands. Each menu corresponds to a basic type of operation that you can perform.These will be described later in this chapter.

Throughout this manual, and in the SAP200 help facility, menu commands are indi-cated as Menu > Command, where “Menu” is the menu name, and “Command”is a item you can select from the menu. In some cases, commands are on sub-menusof the main menu, in which case they are indicated as Menu > Sub-menu > Com-mand.

Toolbars

The buttons on the toolbars provide quick access to many commonly used opera-tions. If you hold your mouse cursor over one of these buttons, a “tool tip” will popup showing you the function of the button, as shown below:

18 The SAP2000 Screen


Most buttons correspond to menu commands. If a menu command has a corre-sponding button, it will be displayed next to the command on the menu, as shown inthe figure below. This allows you to quickly learn which buttons to use for opera-tions that you perform frequently.

You can move the toolbars around to any of the four sides of the main window, orhave them floating over the display windows. You can also control which toolbarsare present and which buttons they contain, and create your own custom toolbars offrequently used operations.

Display Windows

Display windows show the geometry of the model, and may also include properties,loading, analysis or design results. You may have from one to four display windowspresent at any time.

The SAP2000 Screen 19

Chapter IV The Graphical User Interface

Each window may have its own view orientation, type of display, and display op-tions. For example, the undeformed shape could be displayed in one window, ap-plied loads in another, an animated deformed shape in a third, and design stress ra-tios in the fourth window. Alternatively, you could have four different views of theundeformed shape or other type of display: a plan view, two elevations, and a per-spective view.

Only one display window is “active” at a time. Viewing and display operations onlyaffect the current active window. You may make any display window active byclicking on its title bar or within the window.

Status Line

The status line contains the following items:

• Status information about what the program is currently doing, or the number ofobjects currently selected

• The coordinates of the mouse cursor

• A drop down box to show or change the current units

• A drop down box to show or change the current coordinate system

• Scrolling controls when displaying analysis results for multi-step cases

• Animation controls when displaying deformed shapes

Using the MouseThe left and right mouse buttons have different functions depending on where youare pointing the mouse in the graphical user interface.

In the menu and toolbar areas, the mouse buttons have the following functions:

• Left button

– Select commands from the menus or toolbar buttons.

– Move the toolbars around.

• Right button: To customize the toolbars.

Clicking either mouse button in a display window makes that window active.Within a display window, the mouse buttons have the following functions:

20 The SAP2000 Screen


• Left mouse button: depending on which mode the program is in, this button isused to

– Draw new objects,

– Select existing objects,

– Perform graphical operations such as pan, zoom, and rotate.

• Right mouse button:

– When clicked on an object, this button brings up information about the ob-ject,

– When clicked on the background, this button brings up a menu of opera-tions you can choose.

Elsewhere in the interface, the mouse buttons have standard Windows functions.This includes when on the title bar, the status line, and in all forms (dialog boxes.)

Viewing OptionsYou may set various view options for the active Display Window to control how thestructure appears in that window. These options are available in the View menu.View options are set independently for each Display Window.

2-D and 3-D Views

A 2-D view consists of a single plane or surface. Only objects in that plane or sur-face are visible. You may change the out-of-plane coordinate of the view at anytime. Default 2-D views are available at grid points in the current coordinate sys-tem. You can also create your own 2-D views, including developed elevations.

A 3-D view shows the whole model from a vantage point of your choice. Visibleobjects are not restricted to a single plane. The view direction is defined by an anglein the horizontal plane and an angle above the horizontal plane.

Perspective

A 3-D view may be toggled between a perspective view and an orthographic pro-jection. The perspective view is usually better for visualizing the third, out-of-plane, dimension. If perspective is turned on for a 2-D view, the view becomes 3-Duntil perspective is turned off again.

Viewing Options 21


You may set the perspective aperture angle which defines how close you are to thestructure. The larger the angle, the closer you are, and the more distorted the struc-ture may appear.

Pan, Zoom, and 3-D Rotate

You may zoom-in to a view to see more detail, or zoom-out to see more of the struc-ture. Zooming in and out may be done in predefined increments. You may alsozoom-in to a part of the structure that you define by dragging a window with themouse while holding down the left mouse button.

Panning allows you to dynamically move the structure around the Display Windowby holding down the left mouse button while dragging the mouse in the window.

You can use the 3-D Rotate command to dynamically rotate the structure by hold-ing down the left mouse button while dragging the mouse in the window.

Limits

You may set upper and lower X, Y, and Z coordinate limits that restrict the portionof the structure that is visible in a Display Window. Zooming and panning only ap-ply to the part of the structure within these limits.

Element View Options

You may control what types of objects are present in a Display Window. You mayalso set various options that affect how these objects appear and what features aredisplayed, such as object labels, property labels, and local axes. These options pri-marily affect views of the undeformed shape.

Only objects that are present in a Display Window can be selected graphically. Seeselection operations, discussed later in this chapter.

Objects may be shown by edges, area fill, or as 3-D shaded images. You can choosewhether to color the objects according to their type, section properties, materialproperties, or groups.

An important option is the shrunken-object view. This shrinks the objects awayfrom the joints allowing you to better see the connectivity of the model. Whenviewing analysis results, the analysis elements are shrunk rather than the model ob-jects, allowing you to see how the program automatically meshed the structure.

22 Viewing Options


Other Options

You may turn gridlines and the global axes on and off. You may save view parame-ters under a name of your choice, and recall them later to apply to any Display Win-dow.

Refreshing the Display Window

After performing certain operations, the Display Window may need to be re-drawn.Normally this is done automatically, but you may use the Options menu to turn thisfeature off in order to save you time when working with large models. In this case,use the menu command View > Refresh Window whenever you would like the ac-tive display window to be re-drawn and updated.

Basic OperationsIt will be helpful for you to understand the basic types of operations that you canperform with SAP2000. The program responds differently to mouse actions in thedisplay windows depending upon the type of operation you are performing.

The remainder of this chapter provides an overview of SAP2000 operations. De-tails on how to actually perform these operations are given in the quick tutorial inthe next manual, and in the on-line Help facility of the graphical user interface it-self.

File OperationsFile operations are used to start a new model, to bring in an existing model for dis-play or modification, to save the model that you are currently working on, and toproduce output. File operations are selected from the File menu.

New models can be started from scratch or from pre-defined templates suppliedwith the program.

A model and its results can be saved as a standard SAP2000 binary file (.SDB ex-tension), and opened again later to review results or make further changes.

Alternatively, a model and its results can also be exported, in whole or in part, to atext file, a spreadsheet file, or a database file using SAP2000 tabular data format.Models can be imported using SAP2000 tabular data format, whether the data file

Basic Operations 23


(text , spreadsheet, or database) was previously exported from the graphical user in-terface, or created externally in some other way.

Model geometry can be exported to and imported from AutoCAD and other pro-grams that use .DXF file formats. Similar import/export capabilities are availablefor the FrameWorks Plus CAD program. SAP2000 can also export to and importfrom steel detailing programs using CIS/2 Step or Steel Detailing Neutral File for-mats.

The model description and the results of analysis and design can be printed in sim-ple tables or produced in custom reports that include graphics, text, and formattingfeatures. The active display window can be printed as graphics or saved in bitmapand enhanced Windows metafile formats. Video files can be created showing ani-mated mode shapes or time-history deflected shapes.

Other file operations include defining project information for the particular model;maintaining a detailed log of the project; and a facility for running the analyses ofmultiple models in batch mode.

Defining Named EntitiesDefining is used to create named entities that are not part of the geometry of themodel. These entities include:

• Object properties, such as

– Material properties

– Frame/Cable, Area, Solid, and Link properties

– Hinge properties

• Coordinate/grid systems

• Joint constraints

• Object groups

• Load-related items, such as

– Joint patterns, for temperature and pressure loading

– Load cases

– Mass source

– Bridge loads (vehicles and lanes)

– Response-spectrum and Time-history functions

24 File Operations


• Analysis and response items, such as

– Analysis cases

– Combinations

– Generalized displacements

– Section cuts

• Output and display items, such as

– Named views, for display window settings

– Named sets, for output and export definition

Defining these entities is performed using the Define menu and does not require aprior selection of objects.

Object properties, groups, and some of the loading can be assigned to selected ob-jects. Many of these entities can also be defined during the assignment operationfrom the Assign menu.

The remaining entities apply to the model as a whole and are not assigned to ob-jects.

DrawingDrawing is used primarily to add new objects to the model or to modify objectsone-at-a-time. Objects you can draw include points (joints and grounded links),lines (frames, cables, and connecting links), and areas (shells, planes, asolids). Youcannot draw solid objects, but must create them by extrusion; see topic “Editing”below.

Joints are automatically created at the ends of line and link objects and at the cor-ners of area and solid objects. Additional joints may be added explicitly. Duplicatejoints and objects at the same location are automatically eliminated by the program,except that duplicate link objects are permitted as an option.

To draw, you must put the program into Draw Mode by selecting one of the objectdrawing commands from the Draw menu. While drawing, you can choose variousdrawing options from a form that floats over the display windows. These includethe properties to assign while drawing and drawing controls. You can move or closethis form if it is in the way while drawing.

Draw Mode and Select Mode are mutually exclusive. To return to Select Mode, usethe menu command Draw > Set Select Mode, or perform any selection operation.

Drawing 25


While drawing, you can use the left mouse button to zoom, pan, or rotate, afterwhich the program will return to draw mode.

Drawing Objects

You use the left mouse button to perform drawing operations. You may need toclick, double-click, or click-and-drag (hold down the left button while moving themouse), depending on the drawing operation:

• Draw Special Joint – Click once to draw a joint, or drag a window to draw jointsat all enclosed grid intersections.

• Draw Frame/Cable – Click once to draw each end point in a series of objectsconnected end-to-end, then double click to end the series

• Quick Frame/Cable – Click once on a grid segment to draw an object, or drag awindow to draw objects on all enclosed grid segments

• Quick Draw Braces – In a 2-D view, click in a grid space (bay) to draw diagonalframe/cable braces

• Quick Draw Secondary Beams – In a 2-D plan view, click in a grid space (bay)to draw a set of secondary beams (frame objects)

• Draw Quad Area – Click once at the four corner locations to draw aquadrilateral, or double-click at the third corner to draw a triangle

• Draw Rectangular Area – In a 2-D view, click once at two opposite corners todraw the object

• Quick Draw Area – Click in a grid space (bay) to draw an area object, or drag awindow to draw objects on all enclosed grid spaces

• Draw 1 Joint (Grounded) Link – Click once to draw a joint, or drag a window todraw joints at all enclosed grid intersections.

• Draw 2 Joint (Connecting) Link – Click once to draw each end point in a seriesof objects connected end-to-end, then double click to end the series

• Quick Draw 2 Joint (Connecting) Link – Click once on a grid segment to drawan object, or drag a window to draw objects on all enclosed grid segments

• Reshape objects – Click once on an object that you want to reshape, then clickand drag the part of an object you want to move.

In 3-D views cursor placement is limited to known locations, such as on gridlinesand at existing point objects. In 2-D views, cursor placement can be anywhere,since the third (out-of-plane) dimension is known.

26 Drawing


Cursor movements can be controlled by using “snap” and “drawing control” toolsduring drawing and reshaping of objects.

Snap Tools

Snap tools find the closest snap location to your pointer as you move it over yourmodel. The snap tools are a fast and accurate way to draw and edit objects. The snaptools can be turned on and off as you draw. More than one snap tool can also beturned on at the same time giving you a choice of snap locations. Options includesnapping to:

• Point objects and grid intersections

• Object ends (corners) and midpoints (mid-edges)

• Object intersections

• Perpendicular projection to a line object or the edge of an area or solid object

• Line objects and the edges of area and solid objects

• Fine grid, and invisible, three-dimensional grid of uniformly-spaced points thatyou define

Drawing Controls

In 2-D views, the drawing control tools provide the capability to enforce the place-ment of a point along specified lines that pass through the last drawn point. Draw-ing controls include:

• Constant H – The line is drawn parallel to the axis that appears horizontal inthe 2-D view

• Constant V – The line is drawn parallel to the axis that appears vertical in the2-D view

• Constant A – The line is drawn at a constant angle to the axis that appears hori-zontal in the 2-D view

• Constant L – The line is drawn at a constant length, measured in the 2-D view

• Constant S – The line is drawn at a constant angle and a constant length, mea-sured in the 2-D view

• Constant D – The line is drawn at constant lengths along the axes that appearhorizontal and vertical in the 2-D view

Drawing 27


You may select the drawing control from the floating form that appears while draw-ing, or press the corresponding letter key (“H”, “V”, “A”, etc.) on the keyboard.Pressing the space bar on the keyboard cancels the drawing control.

Snaps can optionally be used in conjunction with drawing controls. Only the un-constrained component of the selected snap point is used when a control has beenselected.

SelectingSelecting is used to identify existing objects to which the next operation will apply.

SAP2000 uses a “noun-verb” concept where you first make a selection of objects,and then perform an operation upon them. Operations that require you to make aprior selection include certain Editing, Assignment, Design, Display, and Outputoperations.

To select, you must put the program into Select Mode. Do this by using the menucommand Draw > Set Select Mode, or by choosing any command from the Selectmenu. Draw Mode and Select Mode are mutually exclusive. Any operation exceptdrawing can be performed when the program is in Select Mode.

You can select objects graphically or by various features of the objects. Selectionoperations are cumulative, i.e., each selection operation adds objects to the currentset of selected objects, and each deselection operation removes objects from the set.

Selected objects are shown graphically in the display windows with dashed lines.The number of selected objects of each type is shown in the status line. It is always agood idea to check the status line when performing selection operations.

Once you have finish building up your selection set (the “noun”), you can performan operation (the “verb”) upon it. This then clears the selection, and you are ready tostart a new selection for the next operation.

Three important selection commands are available from the menu or the toolbar:

• Select > Select > All – selects every object in the model, regardless of what ob-jects are shown in the display windows

• Select > Get Previous Selection – selects the same objects as in the last com-plete selection operation

• Select > Clear Selection – deselects all objects

Other selection (and deselection) operations are described below.

28 Drawing


Selecting Graphically

You can select graphically using the left mouse button in a display window. Severaltypes of graphical selection are available:

• Select by pointer – Click on an unselected object to select it, or click on aselected object to deselect it

• Select by enclosing window – Drag a window from left to right to select all ob-jects that are fully enclosed in the window

• Select by intersecting window – Drag a window from right to left to select allobjects that are fully or partially enclosed in the window

• Select by intersecting line – Drag a line to select all objects that are intersectedby the line

• Select by 3-D box – Click on two points in a 3-D view to select all objects en-closed within a box whose diagonal is defined by the two points and whosesides are parallel to the X, Y, and Z axes.

The first three options are available by default and are indicated by the usual pointercursor. The last two options require that you set the type of selection from the Selectmenu or the toolbar. These options are indicated by special cursors. After a singleselection, the cursor returns to the default pointer/window selection mode.

Only objects present in a given display window can be selected graphically. For ex-ample, suppose you have hidden point and line objects, and are only displaying areaobjects in a particular display window. If you select by dragging a window aroundthe entire structure, only area objects will be selected, even if hidden point and lineobjects actually exist inside the selection window.

While selecting, you can use the left mouse button to zoom, pan, or rotate, afterwhich the program will return to select mode.

Selecting by Feature

From the Select menu, you may select or deselect objects by their various features,such as:

• All objects on a particular plane

• All objects that have a given section or property type

• All objects that belong to the same group

• All objects that connect to the same constraint

Selecting 29


• All objects that have specified labels

These selection methods operate independently of the display windows, and affectall objects having the given feature even if it is not being displayed.

The use of groups is particularly helpful when making complicated selections. Ifyou expect to select the same set of objects more than once, build up your selectionset once and then assign a new group name to the selected objects (see below). Afterthat, you can make the same selection simply by using the group name.

EditingEditing is used to make changes to the model. Most editing operations work on aprior selection of objects. You can perform the following editing operations, all se-lected from the Edit menu:

• Cut or Copy the geometry of selected objects to the Windows clipboard. Ge-ometry information put on the clipboard can be accessed by other programs,such as spreadsheets

• Paste object geometry from the Windows clipboard into the model. This couldhave been edited in a spreadsheet program from a previous Cut or Copy

• Delete selected objects

• Replicate selected objects in a linear or radial array

• Move selected objects to a new location

• Extrude selected objects to create higher dimensional objects:

– Extrude points to lines

– Extrude lines to areas

– Extrude areas to solids. This is the only way to graphically create solidobjects

• Mesh (divide) selected objects into smaller objects of the same type

• Connect or disconnect selected objects at a common joint

• Add to the model from a template

• Interactively edit the model in tabular data format

• Change labels of objects and other named entities

• and more

30 Selecting


Pasting and adding to the model from a template do not operate on a selection of ob-jects. Interactive table editing and changing labels can work on a selection or thewhole model. All other operations require a prior selection to be made.

AssigningAssignment is used to assign properties and loads to one or more objects that youhave just selected. Assignment operations are selected from the Assign menu, in-cluding:

• Assigning properties to joint objects, including restraints, constraints, springs,masses, and local coordinate systems

• Assigning properties to frame/cable objects, including section properties, endreleases, local coordinate systems, end offsets, insertion points, output loca-tions, internal prestressing patterns, cable properties, nonlinear properties, au-tomated meshing parameters, and more

• Assigning properties to area objects, including section properties, local coordi-nate systems, area springs and masses, automated meshing parameters, andmore

• Assigning properties to solid objects, including section properties, local coor-dinate systems, surface springs, automated meshing parameters, and more

• Assigning properties and local coordinate systems to link objects

• Assigning loads of many different types to each type of object

• Assigning pattern values to joints for use in defining temperature and pressureloads

• Assigning group names to objects, making the objects part of that group

• Copying assignments from one selected object, and in a separate operation,pasting these assignments onto one or more selected objects of the same type

Undo and RedoSAP2000 remembers all drawing, editing, and assignment operations that you per-form. It is possible to Undo a series of actions previously performed. If you havegone too far in the Undo process you may Redo those actions. Undo and Redo areaccessed from the Edit menu.

Important notes:

Assigning 31


• Undo does not apply to define operations

• Undo does not apply to interactive table editing

• Once you save the model, run an analysis, or use interactive table editing, youcannot undo prior operations

AnalyzingAfter you have created a complete structural model using the operations above, youcan analyze the model to determine the resulting displacements, stresses, and reac-tions due to the loads applied in the analysis cases.

Before analyzing, you may set analysis options from the Analyze menu. These op-tions are:

• Set available degrees of freedom for the analysis, which are primarily used torestrict a model to planar behavior

• Set whether the model definition and analysis results should be automaticallysaved in SAP2000 tabular format to an Access database file

To run the analysis, use the menu command Analyze > Run. You may select whichcases are to be run. Any cases that have already been run do not have to be runagain. Any cases that you do not run can be run later.

If you choose to run an analysis case that requires results from another case, the pre-requisite case will be run first if it hasn’t been already. For example, if you run a re-sponse-spectrum case, the case that defines the modes used will also be run ifneeded.

Before running the analysis, SAP2000 saves the model. During the analysis, mes-sages from the analysis engine appear in a monitor window. When the analysis iscomplete, you may review the analysis messages using the scroll bar on the monitorwindow. Click on the OK button to close the monitor window after you have fin-ished reviewing these messages. These messages are also saved in a file with exten-sion .LOG, which you can view later using the menu command File > Show In-put/Output Text Files.

No other SAP2000 operations may be performed while the analysis is proceedingand the monitor window is present on the screen. You may, however, run otherWindows programs during this time.

32 Undo and Redo


DisplayingDisplaying is used to view the model definition and analysis results. Graphical dis-plays, tabular displays, and function plots are all available. All display types may bechosen from the Display menu, except that displaying of design results is per-formed using the Design menu.

Graphical Displays

You may select a different type of graphical display for each Display Window.Each window may also have its own view orientation and display options.

Model Definition

You may view the model geometry using the menu command Display > ShowUndeformed Shape. This displays only the objects and assignments that you havechosen using the command View > Set Display Options. All other assignments tothe objects may be viewed using commands Show Load Assigns and Show MiscAssigns in the Display menu.

When viewing the undeformed shape, with or without assignments, a right clickwith the mouse on any object brings up an information form showing all the detailsof geometry, connectivity, assignments, and loads for that object.

Analysis Results

Analysis results can be graphically displayed for any case that has been run. Thesedisplays include:

• Deformed shapes

• Reactions and spring forces for joints

• Force and moment diagrams for frames, cables, and links

• Force and moment stress-resultant contour plots for shells

• Stress contour plots for shells, planes, asolids, and solids

• Influence-lines for displacements, reactions, spring forces, and frame/cableforces and moments

• Virtual work plots for all object types

Deformed shapes can be animated using the controls on the status line. Animatingthe deformed shape sometimes helps to clarify the behavior of the structure.

Displaying 33


For analysis cases with multiple results (multiple modes or multiple steps), you canstep through the individual results using the scrolling controls on the status line.You also have the option to plot the maximum or minimum over multiple steps.

Details of the displayed results can be obtained by clicking on an object with theright mouse button.

Function Plots

Function plots are graphs of one variable against another. These include:

• Response-spectrum curves – These curves can be generated at any joint in thestructure based on the results of a time-history analysis case.

• Plot-function traces – These are general plots of any number of response quan-tities (displacements, stresses, etc.) against time or against another responsequantity. These are available for any time-history or multi-stepped nonlinearstatic case.

• Static pushover curve – This is a plot of a single displacement measure againstthe base reaction for multi-stepped, displacement-controlled nonlinear staticanalysis cases.

Function plots are displayed in a special plot window and may be printed. Tables ofplotted values may also be printed or saved in a file.

Tabular Displays

From the Display menu, you can show the model definition, analysis results, anddesign results as tabular data on screen. You can choose what tables you want tosee. If you make a prior selection, only data for the selected objects are displayed.Otherwise results are produced for the whole model.

Advanced options exist to control the format of the tables, and to create filters thatwill only display data that satisfy specified criteria. An example of this would be todisplay only frame design stress ratios that are above 0.9.

Tabular data can also be exported and printed from these on-screen displays, or byusing commands available on the File menu.

34 Displaying


DesigningDesigning is used to check concrete, steel and/or aluminum frame/cable objectswith respect to different design-code requirements. Design may be performed afterthe structure has been analyzed. Most design operations, including display, areavailable from the Design menu.

Steel and aluminum frame objects can have a minimum weight section automati-cally picked from a set of sections that you have defined. Concrete frame objectscan have the area of longitudinal and shear reinforcing steel automatically chosenaccording to the selected design code.

You can interactively design individual members, trying different sections andchecking the results. If you manually change a section, or if optimum sections wereautomatically chosen by the program, you should re-run the analysis and repeat thedesign process until the analysis and design sections are the same.

Graphical displays of stress ratios and design parameters are available. Tabular de-sign information can be obtained for single frame objects by clicking on them withthe right mouse button. Alternatively, tabular design information can be displayedfrom the Display menu and printed or exported from the File menu. If you make aprior selection, only selected objects are displayed, printed, or exported. Otherwiseresults are produced for the whole model.

Locking and UnlockingAfter an analysis is performed, the model is automatically locked to prevent anychanges that would invalidate the analysis results and subsequent design resultsthat may be obtained. You may also lock the model yourself at any time to preventfurther changes to your model, or unlock the model to permit changes. Lock andUnlock are accessed from the Options menu.

When you unlock the model after an analysis, you will be warned that all analysisresults will be deleted. If you do not want this to happen, save the model under a dif-ferent name before unlocking it. Any subsequent changes will then be made to thenew model.

You are allowed to define analysis cases without unlocking the model. New casescan be added, and cases that have not been run can be modified or deleted with noeffect. If you modify or delete a case that has already been run, analysis results forthat case and all cases that depend upon it will be deleted.

Designing 35


Entering Numerical DataWhen entering data in a form (dialog box), all numerical values by default use theunits shown on the status line. Some forms provide a units option directly on theform, which supersedes the setting on the status line.

You may specify different units directly with the numerical value. For example,suppose meter units were in effect, either from the status line or the form itself. Ifyou enter “3500 mm”, the value would be converted to 3.5.

When force, length, and/or temperature units are mixed, you should list all unitsused, separated by commas and/or spaces, in the following order: force, length,temperature. For example, a modulus of elasticity (force/length2) could be speci-fied as “30000 kip in”, and a moment (force-length) could also be specified as“30000 kip in”. Note that you only need the names of the units, without indicating ifthey are multiplied, divided, squared, etc.

As a special case, length values can be entered in U.S. architectural units as feet andinches, as in the following example format: 9’-3”. The (’) for feet is required, butthe dash (-) and the (”) for inches are optional.

You may also use formulas when entering data. For example, you can specify a datavalue as “1000+40” or as “100*sin(30)”. If you specify units with a formula, besure to leave a space after the formula before the units, e.g., “1000+40 m”. The for-mula is evaluated first before the units are applied, so you cannot use different unitsin different parts of the formula.

A complete calculator is available for more complicated entries. Double-click onthe numerical field while holding down the Shift key to bring up the calculator. Usethe menu command View > Show All on the calculator form itself to see its full ca-pabilities.

Setting OptionsThere are many options that you can set to control how the program behaves. Theseare accessed from the Options menu, and include:

• Dimensions and tolerances – merge, selection, and snap tolerances; font sizes;zoom increment; and others

• Design codes and their parameters

• Colors of objects and results for display and printing

36 Entering Numerical Data


• Formatting for tabular data

• How many display windows to show

• Other display options that affect all display windows

• Locking and unlocking of the model

• Aerial view window, which allows for quick pan and zoom

• And more

Getting HelpTo access the SAP2000 Help facility, use the menu command Help > Contents &Index, or press the F1 key at any time.

If a form (dialog box) is open, the F1 key will take you directly to information abouthow to use that form. Otherwise the F1 key simply opens the Help facility, allowingyou to:

• Browse through the many topics using the Table of Contents

• Use the Index to display an alphabetical list of all Help topics

• Use the Search feature to find topics that contain specific words

From the Help menu you may also access all SAP2000 documentation in AdobeAcrobat .PDF file format, or go to the CSI web site.

The menu command Help > About SAP2000 tells you the version of the programyou are using, as well as information about your operating system. This informationis very useful when contacting CSI for technical support.

Getting Help 37


38 Getting Help


C h a p t e r V

Working with Data Tables

All SAP2000 data that can be accessed using the graphical user interface can alsobe accessed as tabular data, i.e., as data organized in a set of tables with specified ta-ble names and column headings. These data include the definition of the model andthe results of analysis and design. Tabular data can be used for editing or display inthe graphical user interface, for export to and import from other programs, and forgenerating printed output in a variety of formats.

Classification of Tabular DataSAP2000 tabular data is divided into three distinct classes, as described below.

Model Definition

Model definition data include all components of the structural model (properties,objects, assignments, loads, analysis cases, design settings, etc.), as well as any op-tions you have selected, and named result definitions you have created.

Model definition data are always available, whether or not analyses have been runor design has been performed. These tables can be edited, displayed, exported, im-ported, and printed.

Classification of Tabular Data 39

Analysis Results

Analysis results data include the deflections, forces, stresses, energies, and other re-sponse quantities that can be produced in the graphical user interface. These dataare only available for analysis cases that have actually been run. Analysis results ta-bles can be displayed, exported, and printed, but not edited or imported.

Design Results

Design results data include the design stresses, stress ratios, effective lengths, opti-mal sections, area of reinforcing steel, and all other calculated quantities resultingfrom the design process. These data are only available for objects that have actuallybeen designed. Design results tables can be displayed, exported, and printed, butnot edited or imported.

Tables and FieldsSAP2000 tabular data is organized into a set of prescribed (pre-defined) tables.There are different tables for each of the three classes of data described above. Eachtable has a prescribed name.

Examples of model-definition tables are “Joint Coordinates” and “Connectivity -Frame/Cable”. Examples of analysis-results tables are “Joint Displacements” and“Element Forces - Frames”. Examples of design-results tables are “Concrete De-sign 1 - Column Summary Data - ACI 318-99” and “Steel Design 3 - Shear Details -AISC-LRFD93”.

There is a prescribed set of field names that are permitted for each table; these be-come the column headings. The columns may be arranged in any order, and not allfields are always required. Examples of field names for the “Joint Coordinates” ta-ble are “Joint”, “CoordSys”, and “Z”. Associated with the column headings may bethe units used for all data in that column.

Data is entered into the table in one or more rows. Each row contains data in thesame order as the field names (column headings).

The figure on the next page shows an example of the “Connectivity - Frame/Cable”table, with its four fields “Frame”, “JointI”, “JointJ”, and “Length”. The units usedare shown with the column headings. Eleven rows of data are entered in the table,listing frame objects and the two joints to which they connect. The calculatedlength of each object is also given.

40 Classification of Tabular Data


Uses for Tabular DataSAP2000 produces tabular data for two distinct purposes:

• Formatted for presentation, i.e., for display and printing

• Structured as a database for use and modification by computer programs

These are described next in more detail.

Formatted Tables for Presentation

You can display SAP2000 data tables on-screen in the graphical user interface, orgenerate printable files of data tables in one of the following formats:

• Rich text format for Microsoft Word

• HTML format for Microsoft Internet Explorer

• Plain (ASCII) text

Uses for Tabular Data 41

Chapter V Working with Data Tables

• Microsoft Excel (during on-screen display only)

• Microsoft Access (during on-screen display only)

You have complete control over how the tables are to be formatted, as described intopic “Format Control for Display and Printing”.

For more information on generating formatted tables, see topics “Displaying Tabu-lar Data”, “Printing Tabular Data” and “Custom Report Writer.”

Structured Database Tables

You can edit SAP2000 data tables on-screen in the graphical user interface, orexport and import structured tabular database files in one of the following formats:

• Microsoft Access database

• Microsoft Excel spreadsheet


Unlike printable output, the format of these tabular database files is strictly con-trolled in order to allow SAP2000 and other programs to read the data.

See topics “Interactive Table Editing”, “Exporting Tabular Data” and “ImportingTabular Data” for more information on working with database tables.

Displaying Tabular DataAt any time while working in the SAP2000 graphical user interface, you may dis-play available data in tabular format. From the Display menu, you can choosewhether you want to show model definition, analysis results, design results, or amixture of all three classes of data. The figure on the previous page shows an exam-ple of a displayed table.

From each class of data, you may choose specific types of data, which, in turn, de-termines the actual tables that are displayed. The figure on the next page shows theform used to select model definition tables. Similar forms are used for analysis re-sults and design results. Each box you check corresponds to one or more tables thatwill be used to display the chosen data. If you plan to choose the same set of tablesrepeatedly, you can save your settings as a named set which can be used later fordisplaying, printing, and other tabular data operations.

42 Uses for Tabular Data


If you make a selection of objects before display, only the selected objects will beshown in those tables that contain object-specific data. Otherwise the entire modelwill be used.

While displaying tabular data, you can print the tables directly to your defaultprinter in plain text format. You can also open and view the tables using any of thefollowing programs that are available on your computer:

• Microsoft Word as rich text format

• Microsoft Internet Explorer as HTML format

• The default text editor as plain text

• Microsoft Excel

• Microsoft Access

From these programs you can print the tables. However, any changes you make tothe tables cannot be brought back into the SAP2000 model while displaying. Seetopic “Interactive Table Editing” below for how to edit tabular data.

Displaying Tabular Data 43



It is recommended that you not try to import Excel spreadsheet and Access databasefiles created during tabular display, since any formatting applied to them for dis-play purposes may cause an error upon import.

Printing Tabular DataYou can print data tables directly by using the menu command File > Print Tables.As described in the previous topic for displaying tabular data, you can choose thetype of data tables you want to print, and optionally select a portion of the model towhich object-specific tables should apply.

You can print the tables directly to your default printer in plain text format, or youcan generate files that can be opened and printed using any of the following pro-grams:

• Microsoft Word as rich text format

• Microsoft Internet Explorer as HTML format

• The default text editor as plain text


Custom Report WriterCustom Report Writer is an advanced feature in SAP2000 that enables you to createformatted reports using tabular data from SAP2000, along with figures and text.Reports can be created in the following formats:

• Rich text format for Microsoft Word

• HTML format for Microsoft Internet Explorer


Although Custom Report Writer generates formatted output, it uses database tablesthat have been exported from SAP2000 in Microsoft Access database format. Seetopic “Exporting Tabular Data” below. Your report can pull together tables fromone or more database files, which can be from the same or different models.

44 Displaying Tabular Data


You can enter section headings, arbitrary text between the tables, and pictures usingmany different file formats. You have control over the formats of the tables, pagesetup, and fonts to use.

Format Control for Display and PrintingYou can control the format of tables used for display and printing at two distinctlevels.

First, you can use the menu command Options > Tables > Set Default NumberFormatting to specify the units and accuracy desired for each type of numericalitem in the program (e.g., forces, moments, lengths, etc.). For example, you mayspecify that dimensions of the structure are displayed in feet (or meter) units withthree decimal digits, and that section dimensions are displayed in inch (or millime-ter) units with one decimal digit. By default, the program will use the current unitsfor all items, with built-in settings for numerical accuracy.

Secondly, you may control the detailed formatting of each column in each table,such as:

• Which fields are present and in what order

• Column widths and justification

• Units and numerical accuracy

• Sorting of data, i.e., how the rows are ordered

• Other advance features

Your format settings can be saved in a table formats file for later use.

As an aside, note that database tables do not use any of this formatting information,except that database tables in Excel format use the units specified with the menucommand Options > Tables > Set Default Number Formatting.

Interactive Table EditingSometimes it is more convenient to create and edit model definition data in tabularformat than in graphical mode or with standard dialog boxes. This can be done frominside the graphical user interface using the menu command Edit > Interactive Ta-ble Editing. Only model definition data can be edited this way, and the model mustbe unlocked to use this feature.

Format Control for Display and Printing 45


You can choose the types of data to edit, which determines the tables that are avail-able. If you make a selection of objects before editing, only the selected objects willbe available in tables that contain object-specific data.

While you are in interactive table-editing mode, you can make any additions, dele-tions, or modifications you want to the tables you have chosen. When you are done,you must apply these changes to the model, or else quit table-editing mode withoutsaving your changes.

You can type numerical formulas (e.g., 2+3/4) directly into any cell. You can alsoright-click within any field (column) to pop up a useful menu. This menu allowsyou to display a description of the field. If the field expects text-type input then, inmost cases, the menu also allows you to display a drop down list with all acceptablevalues for the selected cell. Finally, if the field expects numeric-type input then themenu allows you to pop up the SAP2000 Calculator.

While working on a table, you can change the units used for a given field by click-ing on the cell just below the column heading. Changing the units for one field willchange the units for other related fields. The units you choose while interactivelyediting tables are temporary. All values will be converted back to the current modelunits once you apply your editing to the model.

You can use the button To Excel on the SAP2000 Interactive Table Editing form tosend the current table to Microsoft Excel, giving you full access to spreadsheetfunctionality to edit the table. When you are finished editing the data in Excel, donot close Excel. Instead, return to SAP2000 and click the From Excel button tosave your changes or the Cancel Excel button to discard them; Excel will automati-cally be closed.

Exporting Tabular DataNormally a SAP2000 model is saved in a binary file with extension .SDB when youuse the menu command File > Save. Analysis results, if any, are saved in a set of bi-nary files in the same folder. These binary files together form a database that is usedwhen you open an existing model with the menu command File > Open. They arein a format that is internal to SAP2000; you cannot access or modify the contents ofthese files except by using the graphical user interface.

In order to provide external access to SAP2000 data, you can export the model defi-nition, analysis results, and design results as a SAP2000 tabular database in any ofthe following file formats:

46 Interactive Table Editing





To export tabular data, use the menu command File > Export, then choose the de-sired file format. Specific details of the different file formats are described in thetopic “Tabular Database File Formats” below. However, they all use the same tablenames and field (column) names, and they all provide the same description of theSAP2000 data.

When exporting, you may choose the classes of data to export and the types of datawithin each class; this, in turn, determines the tables that are written out. If youmake a selection of objects before exporting, only the selected objects will be ex-ported in those tables that contain object-specific data.

You may export as many different files as you want from a given SAP2000 model.Each file may contain different tables and/or may apply to different parts of themodel. These files may be used for processing by other programs, for modificationbefore re-importing to SAP2000, or for any other purpose. However, if you wantthe exported file to contain a complete description of the model, be sure to export allimportable model-definition data for the whole structure.

Importing Tabular DataYou can import model definition data as a SAP2000 tabular database from any ofthe following file formats using the menu command File > Import:




This data could have been exported from the SAP2000 graphical user interface, orcreated by you in some other way. Exporting a model, modifying it, and then re-im-porting the data is useful for parameters studies and for iterative shape-findingproblems. You can also export certain features from one model and import theminto a different model.

Note that the format of an imported file must be consistent with the format used forexporting. If you are contemplating creating your own files for import intoSAP2000, then the best way to see the appropriate format is to create a model in the

Importing Tabular Data 47


graphical user interface and then use the appropriate export command. See topic“Tabular Database File Formats” below for more information.

When importing data into SAP2000 you have the option of importing a new modelor adding to an existing model. If you import a new model then the file should in-clude all importable information for a complete model. However, if you are addingto an existing model then your file can consist of one or more tables.

The “Program Control” table must always be present for the database to be im-ported (otherwise an error will occur). Thus, if you want to import some new jointsinto an existing model your file could consist of only two tables, the “Program Con-trol” table and the “Joint Coordinates” table.

When adding to an existing model, you can choose how to handle conflicts betweenimported data and data that is already present in the model:

• Keep the existing item and ignore the imported item

• Delete the existing item and use the imported item

• Keep the existing item and add the imported item with a new name

Some model definition data is importable, and some is not. For example, the coor-dinates of the joints are importable, as is the connectivity of the frame objects to thejoints. The lengths of the frame objects are included for informational purposeswith the model definition data, but lengths are not importable since they can be cal-culated from the coordinates of the joints to which each object is connected.

Automatic Export During SaveEvery time you save a SAP2000 model, all model definition data is automaticallyexported as tabular database in plain text format to a file with the extension .$2K.This file is also created when you run an analysis, since the program always savesthe model before running.

The .$2K file serves as a text-file backup for the SAP2000 binary .SDB file. Thisfile can be imported as an alternative to opening the .SDB file. Importing the .$2Kfile will not recover analysis or design results, only the complete model definition.

Export During AnalysisYou can request model definition and/or analysis results tables to be exported inAccess database format every time you run an analysis. This can be particularly

48 Importing Tabular Data


useful if you are running a series of analyses for different models using theSAP2000 batch-file option.

To do this, you specify a previously defined named set of model definition tablesand/or a named set of analysis results tables to be exported. Named sets are definedusing the menu command Define > Named Set, or they can be defined while dis-playing or printing tabular data.

Tabular Database File FormatsDatabase tables can be formatted for Microsoft Access, Microsoft Excel, or a texteditor. A tabular database in any of these formats will contain equivalent data.

The database table and field names in SAP2000 can be customized using the menucommand Options > Database > Table and Field Names. See the on-line Help fa-cility in SAP2000 for more information.

Microsoft Access Database

Each SAP2000 table is written as a separate Access database table, with theSAP2000 field names as the column headings.

All tables and fields use one consistent set of units, namely the current units in ef-fect when the file is created. These units are stored in the “Program Control” table,not with the individual fields.

Microsoft Excel Spreadsheet

Each SAP2000 table is written as a separate worksheet in an Excel tabular databasefile. The SAP2000 field names are the column headings. The units associated witheach field are displayed beneath the field names.

For export to Excel, the units are the current units in effect when the file is created,unless you have specified different units with the menu command Options > Ta-bles > Set Default Number Formatting.

For import from Excel, each field (column) may have a unique set of units. For ex-ample, in the “Joint Coordinates” table you could import the X Coordinate ininches, the Y Coordinate in feet and the Z Coordinate in meters. Note that this doesnot apply for import from Access or plain text tabular databases, which use a con-sistent set of units.

Tabular Database File Formats 49


In Excel, the headers are color-coded. Fields that can be imported have yellowheaders. Fields that are ignored upon import have cyan (light blue) headers.

Plain Text File

The Text File Database is always in one consistent set of units. These units are spec-ified in the Program Control table.

The Text File Database consists of a series of tables. Each table has a series of oneor more records (rows). Each record in the table must be on a single data line. Acontinuation character (a blank space followed by an underscore, i.e., _ ) can beused to indicate that a dataline continues on to the next line of text in the file.

Table names are specified by the keyword “TABLE:” followed by a space and thename of the table. The record datalines for a table follow the table-name dataline.A record dataline consists of pairs of data; each data pair is made up of a field namefollowed by the field data. One data pair is required for each field in the table. Alldata pairs for a given record must be on the same data line.

The $ character is used as a comment character. Any data on a given data line thatoccurs after a $ is ignored by the program on import.

Blank lines may occur anywhere and are completely ignored on import. Also, anydata occurring before the first table-name dataline is ignored. Finally, the programwill stop reading the file when it encounters the “End” keyword.

When SAP2000 creates a Text File Database the field data is always enclosed inquotes, whereas the field names are not in quotes. There is no significance to thequotes; they are provided to make the text file easier to read. You can create yourown text files with or without quotes.

If you watch the status bar in the bottom left of the SAP2000 window while import-ing a text file you may notice that the text file is first transferred to a Microsoft Ac-cess file and then the Microsoft Access file is imported into SAP2000.

More InformationDetailed information on using the various menu commands and forms is availableusing the online Help facility in the SAP2000 graphical user interface.

50 Tabular Database File Formats


Complete documentation for any or all tables and fields can be produced using themenu command Options > Tables > Documentation to Word, which creates aMicrosoft Word document that you can open and print.

More Information 51


linear and nonlinear static and dynamic analysis...

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