Etabs User PDF

ETABS
Integrated Building Design Software
User's Guide
Computers and Structures, Inc. Berkeley, California, USA
Version 9 November 2005
Copyright
The computer program ETABS and all associated documentation are proprietary and copyrighted products. Worldwide rights of ownership rest with Computers and Structures, Inc. Unlicensed use of the program or reproduction of the documentation in any form, without prior written authorization from Computers and Structures, Inc., is explicitly prohibited. Further information and copies of this documentation may be obtained from: Computers and Structures, Inc. 1995 University Avenue Berkeley, California 94704 USA Phone: (510) 845-2177 FAX: (510) 845-4096 e-mail: info@csiberkeley.com (for general questions) e-mail: support@csiberkeley.com (for technical support questions) web: www.csiberkeley.com
Copyright Computers and Structures, Inc., 1978-2005. The CSI Logo is a registered trademark of Computers and Structures, Inc. ETABS is a registered trademark of Computers and Structures, Inc. Windows is a registered trademark of Microsoft Corporation. Adobe and Acrobat are registered trademarks of Adobe Systems Incorporated.
DISCLAIMER
CONSIDERABLE TIME, EFFORT AND EXPENSE HAVE GONE INTO THE DEVELOPMENT AND DOCUMENTATION OF ETABS. THE PROGRAM HAS BEEN THOROUGHLY TESTED AND USED. IN USING THE PROGRAM, HOWEVER, THE USER ACCEPTS AND UNDERSTANDS THAT NO WARRANTY IS EXPRESSED OR IMPLIED BY THE DEVELOPERS OR THE DISTRIBUTORS ON THE ACCURACY OR THE RELIABILITY OF THE PROGRAM. THE USER MUST EXPLICITLY UNDERSTAND THE ASSUMPTIONS OF THE PROGRAM AND MUST INDEPENDENTLY VERIFY THE RESULTS.
Contents
Users Guide
1 Program Description
Objective This is ETABS Time Saving Options Templates and Defaults Basic Process Forms 1-1 1-1 1-3 1-3 1-4 1-4
ETABS Screen
Objective The ETABS Window File Operations Edit Viewing Options The Aerial View Define Draw Select Assign 2-1 2-1 2-4 2-4 2-4 2-4 2-5 2-5 2-6 2-6
Users Guide
Analyze Display Design Preferences
2-7 2-7 2-8 2-8
Basic Modes, Drawing Tools, Mouse Pointers

Objective Select or Draw 3-1 3-1
Begin a Model
Objective Create the Basic Grid System Grid Dimensions (Plan) Define a Grid System 4-1 4-1 4-3
Create the Structural Model

Objective Define Story Data Add Structural Objects Using Templates Add Structural Objects Manually Draw Columns Draw Beams Draw Secondary (Infill) Beams Draw the Floor 5-1 5-1 5-2 5-4 5-4 5-6 5-7 5-7
Select Structural Objects

Objective Selection Options Menu Methods of Selecting Objects Deselect Command 6-1 6-1 6-3 6-6
ii
Contents
Get Previous Selection Command Clear Selection Command
6-6 6-6
Load the Structural Model

Objective Structural Loads Define the Static Load Case Name Self-Weight Multiplier Modify an Existing Static Load Case Delete an Existing Static Load Case Assign Structural Loads 7-1 7-1 7-1 7-2 7-3 7-3 7-4
Assign/Change Properties
Objective Properties Auto Select Section List Assign the AUTOLATBM Auto Select Section List Make an Assignment as the Object is Drawn Check the Sections in an Auto Select Section List 8-1 8-1 8-3 8-5 8-6 8-6
Edit the Model Geometry

Objective Editing Options 9-1 9-1
10
Analyze the Model

Objective Model Analysis Locking and Unlocking the Model 10-1 10-1 10-2
iii
Users Guide 11 Design

Objective Design the Structure 11-1 11-1
12
Graphical Displays
Objective Obtain Basic Graphical Displays 12-1 12-1
13
Generate Results
Objective Analysis and Design Results 13-1 13-1
iv
Chapter 1
Program Description
Objective
This chapter briefly describes the program and some of the concepts involved in its use.
This Is ETABS
ETABS is a powerful program that can greatly enhance an engineer's analysis and design capabilities for structures. Part of that power lies in an array of options and features. The other part lies in how simple it is to use. The basic approach for using the program is very straightforward. The user establishes grid lines, places structural objects relative to the grid lines using points, lines and areas, and assigns loads and structural properties to those structural objects (for example, a line object can be assigned section properties; a point object can be assigned spring properties; an area object can be assigned slab or deck properties). Analysis and Objective 1-1
User's Guide
design are then performed based on the structural objects and their assignments. Results are generated in graphical or tabular form that can be printed to a printer or to a file for use in other programs. In using the program, you manage the File, Edit the model, change the View, Define properties or load and analysis cases, Draw something new in the model, Select that something, Assign properties or loads, Analyze the model, Display analysis results for checking, Design the structure, apply various Options to achieve the desired outcome with optimum effort, and seek Help when you need it. Those actions are the basis for the program menu structure. Thus, familiarity with the menu commands and their function is key to expanding your ability to use ETABS.
ETABS Menu Commands:

Information about the various menu items is available using the Help menu > Search for Help on command as well as by using the F1 key when a form is displayed on the ETABS screen. The F1 key will display context sensitive help, including descriptions of the types of input for the forms used in the program. Familiarity with the menu commands will enable the user to create models for complex Composite Floor Framing Systems with Openings and Overhangs, Steel Joist Systems, Moment Resisting Frames, Complex Shear Wall Systems, Rigid and Flexible Floors, Sloped Roofs, Ramps and Parking Structures, Mezzanine Floors, Trussed Systems, Multiple Tower Buildings and Stepped Diaphragm Systems, and many more.
File Edit View Define Draw Select Assign Analyze Display Design Options Help
Technical Notes in .pdf format are available using the Help menu > Documentation and Tutorials command. Those Notes explain how the program performs concrete frame design, steel frame design, composite floor design, steel joist design, and concrete shear wall design in accordance with applicable building codes.
1-2
This Is ETABS
Chapter 1 - Program Description
Time Saving Options

The program also includes options that allow you to reduce the time spent creating models. Those options include the following:
Similar Stories. Allows the user to make changes to multiple stories simultaneously. Snap To. Allows the user to place structural objects with accuracy. Auto Select Sections. Allows the user to define a list of sections, for example W18X35, W18X40, W21X44, W21X50 and W24X55, that can be assigned to a frame member. The program can then automatically select the most economical, adequate section from the auto select section list when it is designing the member. Vertical Load Transfer. Frees the user from the chore of calculating the load on the members supporting the floor plate, and determines the area tributary to each member for live load reduction.
Templates and Defaults

ETABS provides a number of templates that allow for the rapid generation of models for a wide range of common building types. Those templates serve as a good starting point because they can be modified easily. The program also includes templates for two-dimensional and threedimensional frames that can be appended to an existing model. The twodimensional option can be used to locate planar frames throughout a model. The three-dimensional option can assist in modeling conditions where several towers rest on the same base structure. The program includes default parameters, many of which are building code specific. Those defaults are accessed using "Overwrites" and "Preferences." The possible options available for overwrites and the default values for preferences are identified in the design manuals. By using the built-in templates and defaults, the user can create a model in a matter of minutes.
Time Saving Options
1-3
User's Guide
Basic Process
The following provides a broad overview of the basic modeling, analysis, and design processes: 1. Set the units. 2. Open a file. 3. Set up grid lines. 4. Define story levels. 5. Define member properties. 6. Draw structural objects. 7. Assign properties. 8. Define load cases. 9. Assign loads. 10. Edit the model geometry. 11. View the model. 12. Analyze the model. 13. Display results for checking. 14. Design the model. 15. Generate output. 16. Save the model.
Forms
Various forms are used in ETABS throughout the modeling, analysis and design processes. With a form displayed on the ETABS window, click the F1 key on your keyboard to access context-sensitive Help for the form.
1-4
Basic Process
Chapter 2
ETABS Screen
Objective
This chapter briefly describes the ETABS screen or more accurately, the graphical user interface.
The ETABS Window

The ETABS graphical user interface shown in Figure 2-1 includes the main window, main title bar, display title bar, menu bar, toolbars, display windows, status bar, mouse pointer position coordinates and the current units. Each of these items is described in the bulleted list that follows.
Main Window. This window may be moved, resized, maximized, minimized, or closed using standard Windows operations. Refer to Windows help, available on the Start menu, for additional information about those items.
Objective
2-1
User's Guide
Toolbars Main Title Bar
Menu Bar
Display Title Bar (Active Window)
Display Title Bar (Inactive Window) Coordinate System used for Mouse Coordinates Plan View Drawing and Assignments Options (Similar Stories Feature)
Window Separator
Mouse Pointer Position Coordinates Status Bar
Current Units
Figure 2-1: The ETABS graphical user interface
Main Title Bar. The main title bar includes the program and model names. The main title bar is highlighted when the program is in use. Move the main window by left clicking in the main title bar and holding down the mouse button as you drag the window around the computer screen. Menu Bar. The menu bar contains all of the program's menus. Toolbars and Buttons. Toolbars are made up of buttons. Buttons provide "one-click" access to commonly used commands. Holding the mouse pointer over a toolbar button for a few seconds without clicking or holding down any mouse buttons will display a short description of the button's function in a small text box. Display Windows. A display window shows the geometry of the model and may also include displays of properties, loading and analysis or design results. Up to four windows may display at any one time.
2-2
The ETABS Window
Chapter 2 - ETABS Screen Display Title Bar. The display title bar is located at the top of the display window. The display title bar is highlighted when the associated display window is active. The text in the display title bar typically includes the type and location of the view in the associated display window. Status Bar. The status bar is located at the bottom of the main window. Text describing the current status of the program is displayed on the left side of the status bar. Mouse Pointer Position Coordinates. The mouse pointer position coordinates are displayed on the right-hand side of the status bar. A window does not need to be active for the mouse pointer position coordinates to be displayed. It is only necessary that the mouse pointer be over the window. In a two-dimensional plan or elevation view, the mouse pointer position coordinates are always displayed. In a threedimensional view, the mouse pointer position coordinates are only displayed when the mouse pointer snaps to a point or a grid line intersection. "One Story" Drop-Down List. This drop-down list is on the right side of the status bar. The three options in the drop-down list are One Story, All Stories, and Similar Stories. With One Story, an object is applied only to the story level on which it is drawn. With All Stories, an object drawn in the plan view is applied to all story levels in the model at the same plan location. An assignment made to the selected objects also is made to the other objects in the same plan location at all other story levels. With Similar Stories, an object drawn in plan view is applied to all similar story levels in the model at the same plan location. An assignment made to the selected objects is made to the other objects in the same plan location at all similar story levels. Current Units. The current units are displayed in a drop-down list located on the far right-hand side of the status bar. The units can be changed at any time during the model creation process.
The ETABS Window
2-3
User's Guide
File Operations
File operations are used to start a new model, to bring in an existing model for display or modification, to save or export the current model for use in ETABS or another application, and to produce output. File operations are selected from the File menu. New models can be started from scratch or from predefined templates supplied with the program.
Edit
Editing is used to make changes to the model. Most editing operations work with one or more objects that were selected immediately before using the Edit command. Objects may be deleted, copied, pasted, moved, aligned, replicated, merged, meshed, and extruded using edit commands.
Viewing Options
View options, which affect how the structure displays, may be set for each display window and the setting may differ from window to window. Views may be saved and recalled at any time.
The Aerial View

Figure 2-2 shows an example of the aerial view window. This window displays the entire drawing to help you move around the active window of a larger model and use the zoom feature to view smaller areas more easily. Also use the aerial view to track which part of the model is displayed in the active window. Each time the model is edited, the aerial view is updated.
2-4
File Operations
Chapter 2 - ETABS Screen
2
Aerial View
Figure 2-2: Example of the aerial view
Define
Define is used to create named entities that are not part of the geometry of the model. Those entities, accessed from the Define menu, include items such as material properties; frame, wall and slabs sections; and load cases and combinations. Definition of those entities does not require prior selection of an object, and some of those entities can be defined during the assignment operation using the Assign menu.
Draw
Drawing is used to add new objects to the model or to modify one object at a time. Objects include beams, columns, slabs, decks, walls and other point, line and area objects. To draw, the program must be in Draw Mode, which is activated by clicking one of the draw buttons on the toolbar or using a Draw menu command. In Draw Mode, the left mouse button is used to draw and edit objects, and the right mouse button is used to query the properties of those ob-
Define
2-5
User's Guide jects. Depending on the type of object to be drawn, a Properties of Object form appears that can be used to specify various structural properties. As line objects are drawn, frame properties can be assigned simultaneously. Area objects may be assigned floor properties, wall properties, or defined as openings when drawn. After an object has been drawn, the object may be selected and loads may be assigned to it, or existing assignments can be modified. Draw Mode and Select Mode are mutually exclusive. No other operations can be performed when the program is in Draw Mode.
Select
Selection is used to identify those objects to which the next operation will apply. ETABS uses a noun-verb concept; that is, a selection is made and then an operation is performed. Certain editing, assigning, printing and displaying operations require prior selection of an object. To select, the program must be in Select Mode, which is activated by clicking one of the select buttons on the toolbar. Alternatively, selecting any action from the Select menu puts the program into Select Mode. Many different types of selection are available, including selecting individual objects, drawing a window around objects, and selecting by property type. In Select Mode, the left mouse button is used to select objects, and the right mouse button is used to query the properties of those objects. Draw Mode and Select Mode are mutually exclusive.
Assign
Certain assignments may be made when drawing an object, such as assigning a structural property when drawing a line object. However, additional assignments, or changes to assignments, may be made to one or more objects that were selected immediately before using the Assign
2-6
Select
Chapter 2 - ETABS Screen menu command. Assignment operations include properties, restraints, loads and group names.
Analyze
After a complete structural model has been created using the preceding commands, the model can be analyzed to determine the resulting displacements, forces/stresses and reactions. Before running an analysis, use the Set Analysis Options command on the Analyze menu to control the active degrees of freedom and use Check Model to ensure that objects do not overlap and that objects are connected. To run the analysis, select Run Analysis from the Analyze menu, or click the Run Analysis button on the toolbar. The program saves the data, then checks and analyzes the model. During the checking and analysis phases, messages from the analysis engine appear in a monitor window. When the analysis is complete, the scroll bar on the monitor window can be used to scroll through and review the analysis messages. No other ETABS operations may be performed while the analysis is proceeding and the monitor window is present on the screen. However, other Windows applications can be run during this time.
Display
The Display menu commands are used to view the model and the results of the analysis. Graphical and tabular displays are available in this program. Display items may be chosen from the Display menu or accessed using toolbar buttons. Graphical Displays Different types of graphical display may be selected for each display window. Each window may also have its own view orientation and display options. Undeformed geometry, loads and analysis results can all be displayed. Details of the dis-
Analyze
2-7
User's Guide played results can be obtained by clicking on an object with the right mouse button. Tabular Displays Tabular information can be displayed for the model by choosing the Show Tables command. Choose the tables to be viewed. If objects are selected prior to using the commands, certain tables will only be available for the selected objects. If no objects are selected, the tables produced are for the entire model. Tabular data can also be printed using the commands available on the File menu.
Design
After an analysis has been completed, frames, composite beams, joists, and shear walls can be designed with respect to design code requirements. Design may be performed for the given design combinations by choosing the appropriate Design menu command. Before designing, verify the selected design code using the Options menu > Preferences command. Graphical displays of design parameters are available. Tabular design information can also be printed using commands from the File menu.
Preferences
The program allows custom setting of some parameters using the Options menu > Preferences command, including the design code, reinforcing bar sizes, tolerances, and fonts.
2-8
Design
Chapter 3
Basic Modes, Drawing Tools, Mouse Pointers

Objective
This chapter briefly describes the two modes of user operation for the program, identifies the drawing tools, and describes how the appearance of the mouse pointer changes for various operations.
Select or Draw
The two distinct modes in this program are the select mode and the draw mode. The select mode allows objects to be selected and is used for editing operations, making assignments to objects, and viewing or printing results. By default, the program is in select mode. Chapter 6 describes the various methods for selecting points, lines, and areas in a model. The draw mode allows objects to be drawn.
Objective
3-1
User's Guide The draw mode automatically enables when one of the following submenu options from the Draw menu is selected or the corresponding buttons on the toolbar are clicked. Note that the views in parenthesis (Plan, Elev, 3D) after the command name indicate when the button will be active; for example, the Draw Lines command/button can be used in the Plan, Elevation or 3D views, but the Draw Walls command/button can be used only in Plan view. The names of the commands are assumed to explain the actions that will be accomplished. The terminology in Regions means within a bay and at Clicks means at the location of the mouse pointer in the model when the left mouse button is clicked. More information about the Draw tools is available by searching for draw menu using the Help menu > Search for Help on command.

Draw Point Objects Draw Line Objects

Draw Lines (Plan, Elev, 3D) Create Lines at Regions or at Clicks (Plan, Elev, 3D) Create Columns in Regions or at Clicks (Plan) Create Secondary Beams in Regions or at Clicks (Plan) Create Braces in Regions (Elev)
Draw Area Objects

Draw Areas (Plan, Elev, 3D) Draw Rectangular Areas (Plan, Elev) Create Areas at Click (Plan, Elev) Draw Walls (Plan) Create Walls in Regions or at Clicks (Plan)
Draw Developed Elevation Definition
3-2
Select or Draw
Chapter 3 - Basic Modes, Drawing Tools, Mouse Pointers Draw Section Cut Draw Dimension Line Draw Reference Point
The draw mode remains enabled until one of the following actions is taken to return to the select mode:

Click the Pointer button on the toolbar Press the Esc key on the keyboard. Select a command from the Select menu.
The mouse pointer indicates which mode is enabled. The appearance/properties of the mouse pointer are defined in the Windows Control Panel. The mouse pointer properties are Normal Select Pointer and Alternate Select pointer.
Note: Typically, set the properties for the mouse by clicking on the Windows Start menu, then Control panel and clicking on Mouse to access the Mouse properties form.
In select mode, the pointer is the Normal Select Pointer. If the default settings are being used, the mouse pointer will look like this . In draw mode, the mouse pointer is the Alternate Select pointer. If the default settings are being used, the mouse pointer will look like this . Note that while in draw mode, if the mouse pointer is moved over the toolbar buttons or the menus, the pointer temporarily changes to the selection pointer. If during this time one of the menus or toolbar buttons is not clicked, the mouse pointer reverts to the draw mode pointer when it is moved back into the display window. Other mouse properties/appearances are used for various actions in the program, including Help Select, Busy, Text Select, Vertical Resize, Horizontal Resize, and Move. The appearance of the mouse pointers for those actions depends on the mouse pointer properties you specify.
Select or Draw
3-3
Chapter 4
Begin a Model
Objective
This chapter describes how to begin a model by creating the basic grid system. Structural objects are placed relative to the grid system.
Create the Basic Grid System

Begin creating the grid system by clicking the File menu > New Model . The form shown in Figure 4-1 command or the New Model button will display.
Figure 4-1 The New Model Initialization form
Objective
4-1
User's Guide Select the No button on that form and the form shown in Figure 4-2 will display.
Note: More information about templates is available by searching for template using the Help menu > Search for Help on command..
Figure 4-2 Building Plan Grid System and Story Data Definition form
The Building Plan Grid System and Story Data form is used to specify horizontal grid line spacing, story data, and, in some cases, template models. Template models provide a quick, easy way of starting a model. They automatically add structural objects with appropriate properties to the model. We highly recommend that you start your models using templates whenever possible. The form has OK and Cancel buttons, which are used to accept or cancel the selections made on the form. Click the OK button for any selections/entries to be accepted. Clicking the Cancel button cancels any selections/entries.
4-2
Chapter 4 - Begin a Model
Grid Dimensions (Plan) - Define a Grid System

Use the Grid Dimensions (Plan) area of the form to define a grid line system. Select from two options for defining the grid line system:
Uniform Grid Spacing. Specify the number of grid lines in the X and Y directions and a uniform spacing for those lines. Note that the uniform spacing in the X and Y directions can be different. This option defines a grid system for the global coordinate system only. If subsequently necessary, edit the information using the Edit menu > Edit Grid Data > Edit Grid command. For more information, search for edit grid data using the Help menu > Search for Help on command. Note that the default global coordinate/grid system is a Cartesian (rectangular) coordinate system. Custom Grid Spacing. Label grid lines and define nonuniformly spaced grid lines in the X and Y directions for the global coordinate system. After choosing this option, click the Grid Label button to label grid lines and click the Edit Grid button to edit the grid system. For more information, search for grid labeling using the Help menu > Search for Help on command.
The reasons for defining a grid system for the model include the following:
Default elevation views in the model occur at each defined primary grid line in a model. Structural objects added to the model from a template are added based on the grid line definitions in the model. Objects snap to grid lines when drawn in the model. Objects mesh at their intersections with grid lines. The grid lines in the model can be defined using the same names as are used on the building plans. This may allow for easier identification of specific locations in the model.
4-3
5
Chapter 5
Create the Structural Model

Objective
This chapter describes how to create the structural model. It is assumed that you have read Chapter 4 Begin a Model or understand how to begin an ETABS model by defining a grid system.
Define Story Data

Note: The story data of an existing model can be changed using the Edit menu > Edit Story Data > Edit Story command.
Story data is defined using the Plan Grid System and Story Definition form. Figure 4-2 of Chapter 4 shows that form. As described in Chapter 4, use the File menu > New Model command and make a selection on the New Model Initialization form to access the Building Plan Grid System and Story Definition form. Select one of the two options in the Story Dimensions Area of the form to define the story data:
Simple Story Data: Enter values in the edit boxes to define the number of stories and a typical story height that is used for all story levels.
Objective
5-1
User's Guide
Note: Story level similarity can be significant. For example, when Story 2 is Similar To Story 1, an object drawn on Story 1 typically appears in the same plan location on Story 2.
The program provides default names for each story level (for example, Story 1, Story 2 and so on) and assumptions for story level similarity.
Custom Story Data: After choosing this option, click the Edit Story Data button to access the Story Data form. Enter values in the Story Data form to define your own story names, story levels of non-uniform height and customized story similarity.
The Story Data form also appears when the Edit menu > Edit Story Data > Edit Story command is used. For more information about the Story Data form, refer to the Editing chapter of this manual. For more information about story level similarity, search for similar stories dropdown list using the Help menu > Search for Help on command. Story level similarity can also be significant to composite beam and steel joist design. Search for similarity using the ETABS Help menu > Search for Help on command for more information.
Add Structural Objects Using Templates

Use the bottom half of the same Building Plan Grid System and Story Definition form as was used in the previous section to add structural objects to your model from one of several built-in templates. In many cases it is the simplest, most convenient and quickest way to start a model. The Add Structural Objects area of the Building Plan Grid System and Story Definition form is reproduced herein for reference:
Note that the templates consist of two for steel buildings, four for concrete buildings, and one for grids only, which means that no structural
5-2
Chapter 5 - Create the Structural Model objects are added to the model from the template. When an option (button) has been selected in the Add Structural Objects area, its name will be highlighted. When the Building Plan Grid System and Story Definition form opens, the Grid Only selection is highlighted, thus indicating that unless you select another template before clicking the OK button, your model will have only a grid system. Choose any of the templates by left clicking its associated button. When one of the template buttons is chosen, a form for that template appears (except when the Grid Only button is clicked). Use the template form to specify various types of data for your model. When you have finished specifying data on the template form, click the OK button to return to the Building Plan Grid System and Story Definition form. Click the OK button on the Building Plan Grid System and Story Definition form to complete the operation.
Note: When using concrete building templates in this program, beams and slab ribs (joists) are normally modeled with depths equal to the dimension from the top of the slab (not bottom of slab) to the bottom of W the beam or slab rib. Also, beams are modeled as line elements in this h program. Thus, slabs with out-of-plane bending capability span from e center-of-beam to center-of-beam in the program model.
After the OK button on the Building Plan Grid System and Story Definition form has been clicked, the model appears on screen in the main ETABS window with two view windows tiled vertically, a Plan View on the left and a 3-D View on the right, as shown in Figure 5-1. The number of view windows can be changed using the Options menu > Windows command. Note that the Plan View is active in Figure 5-1. When the window is active, the display title bar is highlighted. Set a view active by clicking anywhere in the view window.
5-3
User's Guide
Display Title Bar (active)
Similar Stories
Units
Figure 5-1 The ETABS main window
Add Structural Objects Manually

Objects, such as columns, beams, and floors, also can be drawn manually as described in the sections that follow.
Draw Columns
Make sure that the Plan View is active. Click the Create Columns in , or use the Draw menu > Draw Line Region or at Clicks button, Objects > Create Columns in Region or at Clicks command. The Properties of Object pop-up box for columns shown in Figure 5-2 will display. 5-4 Add Structural Objects Manually
Chapter 5 - Create the Structural Model
Note: The definition parameters and drawing controls available in the Properties of Object box differ depending on the drawing command/ button selected. Always check that the parameters and controls are what you need for the type of object you are drawing.
Figure 5-2 Properties of Object Box for Columns
The Properties of Object box provides various definition parameters and drawing controls. Review the parameters and controls shown in this box before drawing the column to ensure that they are what they should be. Change any entry in the box by clicking on it and making a new selection from the drop-down list or entering new information into the edit box, as appropriate. After checking the parameters in the Properties of Object box, left click once in the Plan View at the intersection of the grid lines where you want the column. An I-shaped column should appear at that point in the Plan View. Continue in this manner to place other columns. Alternatively, draw the remaining columns in one action by "windowing" around the grid intersections. To "window," click the left mouse button above and to the left of the first grid intersection where a column is to be placed and then, while holding the left mouse button down, drag the mouse until it is below and to the right of the last grid intersection where a column is to be placed. A selection box similar to that shown in Figure 5-3 should expand around the grid line intersections as the mouse is dragged across the model. Release the left mouse button and the program will draw the column objects at the grid line intersections within the boundaries of the selection box. It is a good idea to save your models often. Click the File menu > Save command, or the Save button, , to save the model.
5-5
User's Guide
Selection Box
Figure 5-3 Drawing Column Objects in a Windowed Region
Draw Beams
Make sure that the Plan View is active. Click the Create Lines in Reor the Draw menu > Draw Line Objects gion or at Clicks button, > Create Lines in Region or at Clicks command. The Properties of Object pop-up box for beams shown in Figure 5-4 will display.
Figure 5-4 Properties of Object Box for Beams
5-6
Chapter 5 - Create the Structural Model As explained previously, the Properties of Object box provides various definition parameters. Change any entry in the box by clicking on it and making a new selection from the drop-down list or entering new information into the edit box, as appropriate. After checking the parameters in the Properties of Object box, left click once in the Plan View on a grid line where a beam is to be placed. A beam is drawn along the selected grid line. Continue in this manner to place other beams. Alternatively, draw the remaining beams in one action by windowing around the grid intersections. Windowing is explained in the previous section. Click the File menu > Save command, or the Save button, the model. , to save
Draw Secondary (Infill) Beams

Add secondary or "infill" beams by clicking the Create Secondary or the Draw menu > Draw Beams in Region or at Clicks button, Lines Objects > Create Secondary Beams in Region or at Clicks command. Similar to the other drawing operations, a Properties of Object pop-up box will display that provides the opportunity to define the parameters for the secondary beams. To place the secondary beams, left click once in the bay bounded by grid lines where the secondary beams are to be placed. Similar to columns and the primary beams, secondary beams can be drawn by windowing over the appropriate bays. Note the Approx. Orientation parameter to set the span direction. Click the File menu > Save command, or the Save button, the model. , to save
Draw the Floor

Make sure that the Plan View is active. Click the Draw Areas button, , or select the Draw menu > Draw Area Objects > Draw Areas
5-7
User's Guide command. The Properties of Object pop-up box for areas shown in Figure 5-5 will appear.
Figure 5-5 Properties of Object Box for Areas
Similar to columns and beams, this Properties of Object box provides the opportunity to check and change the parameters for the area. Change any entry in the box by clicking on it and making a new selection from the drop-down list or entering new information into the edit box, as appropriate. After checking the parameters in the Properties of Object box, check that the Snap to Grid Intersections and Points command is active. This will assist in accurately drawing the area object. This command is active when its associated button is depressed. Alternatively, use the Draw menu > Snap To > Grid Intersections and Points command to ensure that this command is active. By default, this command is active. Left click once at a column to begin the floor/area object at that column. Then, moving around the perimeter of the floor object, click once at other column intersections to draw the outline of the building. Press the Enter key on your keyboard to complete the floor. If you have made a mistake while drawing this object, click the Select Object button, , to change the program from Draw mode to Select mode. Then click the Edit menu > Undo Area Object Add command. To better view the floor addition, click the Set Building View Options button . When the Set Building View Options form appears, check the Object Fill check box and the Apply to All Windows check box, as shown in Figure 5-6. Click the OK button.
5-8
Chapter 5 - Create the Structural Model
Figure 5-6 Set Building View Options form
Click the File menu > Save command, or the Save button, the model.
, to save
5-9
6
Chapter 6
Select Structural Objects

Objective
This chapter describes how to select objects in the model.
Selection Options
The program has a number of techniques for graphically selecting objects:
Left click: Left click on an object to select it. If multiple objects are present in the same location, one on top of the other, hold down the Ctrl key on the keyboard and click the left mouse button on the objects. Use the form that displays to specify which object to select. Window or "Windowing": Drag a window from left to right to select all objects that are fully enclosed in the window. Drag a window from right to left to select all objects that are fully or partially enclosed in the window. To draw a window, first position the mouse pointer be-
Objective
6-1
User's Guide yond the limits of the object; for example, above and to the left of the object(s) to be selected. Then depress and hold down the left mouse button. While keeping the left button depressed, drag the mouse to a position below and to the right of the object(s) to be selected. Release the left mouse button to complete the selection. Note the following about window selection:
9 As the mouse is dragged, a "rubber band window" appears. The rubber band window is a dashed rectangle that changes shape as the mouse is dragged. One corner of the rubber band window is at the point where the left mouse button was first depressed. The diagonally opposite corner of the rubber band window is at the current mouse pointer position. When dragging the mouse from left to right, any visible object that is completely inside the rubber band window is selected when the left mouse button is released. When dragging the mouse from right to left, any visible object that the window crosses or encloses is selected. 9 As long as the mouse pointer is beyond the limits of the object(s) to be selected, the window can start at any point. Note about Window Selections in Plan View: When selecting by window in a plan view, the objects selected will be determined by the setting in the One Story drop-down list. To select only the objects at the plan level displayed (which include the columns in the story below), the drop-down list should be set to One Story. When set to Similar Stories or All Stories, selecting in plan view may result in objects at other levels being selected, even though only one plan level is displayed.
Intersecting Line: Draw a line through one or more objects to select them. To use this selection method, click the Select menu > Intersecting Line command or the Select using Intersecting Line button, . Then position the mouse pointer to one side of the object(s) to be selected. Depress and hold down the left mouse button. While keeping the left button depressed, drag the mouse across the object(s) to be selected. Release the left mouse button to complete the selection. Note the following about the intersecting line selection method:
6-2
Selection Options
Chapter 6 - Select Structural Objects 9 As the mouse is dragged, a "rubber band line" appears. The rubber band line is a dashed line that changes length and orientation as the mouse is dragged. It extends from the point where the left mouse button is first clicked to the current mouse pointer position. Any visible object that is intersected (crossed) by the rubber band line is selected when the left mouse button is released. 9 After using this method to make a selection, the program defaults to the window selection mode. Thus, the Select menu > Intersecting Line command must be selected or the Select using Intersecting Line button must be clicked each time this selection method is used.
Control and Left Click: Hold down the Ctrl key on the keyboard and left click once on a point, line or area object. A Selection List form similar to the one shown in Figure 6-1 pops up identifying the objects that exist at that location. Select the desired object by moving the mouse pointer over it and left clicking on it.
Figure 6-1 Selection List Form
Menu Methods of Selecting Objects

Table 6-1 identifies the submenu commands and related actions accessed using the Select menu command.
6-3
User's Guide
Table 6-1 Subcommands of the Select Menu Command

Command on XY Plane Action After Command Click on a single point and all objects (point, line and area) that are in the same XY plane as the selected point also are selected. The object must lie entirely in the associated plane to be selected. on XZ Plane Click on a single point and all objects (point, line and area) that are in the same global XZ plane as the selected point also are selected. The object must lie entirely in the associated plane to be selected. on YZ Plane Click on a single point and all objects (point, line and area) that are in the same global YZ plane as the selected point also are selected. The object must lie entirely in the associated plane to be selected. by Groups Select the name of any collection of objects that has been defined as a group from the Select Groups form and that group will be selected. by Frame Sections Select a frame section property name from the Select Sections form and all line objects that have been assigned that frame section property will be selected. by Wall/Slab/Deck Sections Select a wall/slab/deck section property name from the Section Selections form and all area objects that have been assigned that wall/slab/deck section property will be selected. by Link Properties Select a link property name in the Select Properties form and all line objects that have been assigned that link property will be selected.
6-4
Chapter 6 - Select Structural Objects
Table 6-1 Subcommands of the Select Menu Command

Command by Line Object Type Action After Command Select a line objects type from the Select Line Object Type form and all line objects of that type will be selected. The choices for the types of line objects are column, beam, brace, null or dimen lines (short for dimension lines). by Area Object Type Select an area objects type from the Select Area Object Type form and all area objects of that type will be selected. The choices for the types of area objects are floor, wall, ramp or null. Note that openings are a subset of null area objects. by PIER ID Select a Pier Label name from the Select Pier IDs form and any Line or Area that has been assigned that name will be selected. By Spandrel ID Select a Spandrel Label name from the Select Spandrel IDs form and any Line or Area that has been assigned that name will be selected. by Story Level Select a story level from the Story Level form, and all objects (point, line and area) associated with that story level will be selected. All Selects all objects in the model whether they are visible or not. Be careful using this command. It literally selects all objects in the model. Also use the Select All button Invert to execute this command.
Changes the selection such that the currently selected objects are no longer selected and all objects that currently are not selected are selected.
6-5
User's Guide
Deselect Command
Deselect objects one at a time by left clicking on the selected objects. Alternatively, use the Select menu > Deselect command and its subcommands for quicker and more specific deselection actions. This command provides access to subcommands similar to those described in Table 6-1, except that executing the Select menu > Deselect command and an associated subcommand deselects rather than selects an object(s). For example, assume that you want to select all of the objects in your model except for those in a particular XZ plane. Do this quickly and easily by first using the Select menu > All command and then using the Select menu > Deselect > XZ Plane command.
Get Previous Selection Command

The Select menu > Get Previous Selection command selects the previously selected object(s). For example, assume you have selected some line objects by clicking on them and assigned frame section properties to them. Use the Get Previous Selection command or the Get Previous to select the same line objects and assign someSelection button thing else to them, such as member end releases.
Clear Selection Command

The Select menu > Clear Selection command and its associated Clear clear all currently selected objects. It is an all or Selection button nothing command. It cannot selectively clear a portion of a selection.
6-6
7
Chapter 7
Load the Structural Model

Objective
This chapter describes how to define structural loads for the model.
Structural Loads
Note: An unlimited number of static load cases can be Note that the steel frame, concrete frame, composite floor, steel joist, and defined in this concrete shear wall design manuals describe design combinations in acprogram. cordance with building codes.
The program allows the user to define a variety of structural loads, including dead, live, earthquake and wind loads. The user then assigns the loads to various structural objects in the model.
Define the Static Load Case Name

To add a static load case, click the Define menu > Static Load Cases command or click the Define Static Load Cases button, , to access
Objective
7-1
User's Guide the Define Static Load Case Names form. Complete the following actions using that form: 1. Type the name of the load case in the Load edit box. The program does not allow use of duplicate names. 2. Select a load type from the Type drop-down list.
3. Type a self-weight multiplier in the Self-Weight Multiplier edit box (see the explanation about the self-weight multiplier that follows). 4. If the load type specified is Quake or Wind, select an option from the Auto Lateral Load drop-down list. 5. Click the Add New Load button.
Note: If your select an automatic lateral load in the Auto Lateral Load drop-down list, click the Modify Lateral Load button and review or modify the parameters for the automatic lateral load in the resulting form. Then click the OK button to return to the Define Static Load Case Names form.
SELF-WEIGHT MULTIPLIER The self-weight of the structure is determined by multiplying the weightper-unit-volume of each object that has structural properties times the volume of the object. The weight-per-unit-volume is specified in the material properties (search for material properties using the Help menu > Search for Help on command for more information about material properties and the Material Properties command). A portion of the self-weight can be applied to any static load case. The self-weight multiplier controls what portion of the self-weight is included in a load case. A self-weight multiplier of 1 includes the full self-weight of the structure in the load case. A self-weight multiplier of 0.5 includes one-half of the self-weight of the structure in the load case.
7-2
Structural Loads
Chapter 7 - Load the Structural Model Normally a self-weight multiplier of 1 in one static load case only should be specified, usually the dead load load case. All other static load cases then have self-weight multipliers of zero. Note that if a selfweight multiplier of 1 is included in two different load cases, and then those two load cases are combined in a load combination, the results are based on an analysis where double the self-weight of the building has been applied as a load.
Modify an Existing Static Load Case

Use the following procedure and the Define Static Load Case Names form to modify an existing static load case. Recall that the Define Static Load Case Names form is accessed using the Define menu > Static Load Cases command or the Define Static Load Cases button, : 1. Highlight the existing load case in the Loads area of the form. Note that the data associated with that load case appears in the edit boxes and drop-down lists at the top of the Loads area. 2. Modify any of the data in the Loads area for the load case. 3. Click the Modify Load button. If necessary, click the Modify Lateral Load button to modify the automatic lateral load parameters.
Delete an Existing Static Load Case

Use the following procedure to delete an existing static load case in the Define Static Load Case Names form. Note that when a static load case is deleted, all of the loads assigned in the model as a part of that static load case are also deleted.
Highlight the existing load case in the Loads area of the form. Note that the data associated with that load case appears in the edit boxes and drop-down lists at the top of the Loads area. Click the Delete Load button.
Structural Loads
7-3
User's Guide
Assign Structural Loads

The load cases defined in the previous section are required in order to be able to assign loads to points/joints, lines/frames, and areas/shells. The user must first select the object before a load can be assigned to the object. Chapter 6 of this guide describes how to select structural objects.
7
sub menus
After the object has been selected, click the Assign menu command to access the applicable submenu and assignment options. Table 7-1 identifies the submenus and options.
TABLE 7-1 Load Commands on the Assign Menu Joint/Point Loads Force assignment options Ground Displacement Temperature Frame/Line Loads Point Distributed Temperature Open Structure Wind Shell/Area Loads Uniform Temperature Wind Pressure Coefficient
Note that the type of object selected determines which assignment can be made. For example, a ground displacement assignment cannot be made to a frame/line or shell/area object. Thus, if a line/frame object (e.g., a beam) or a shell/area object (e.g., a wall) has been selected before clicking the Assign menu command, the Joint/Point Loads submenu, and thus the ground displacement sub submenu, will not be available. A form will appear after clicking the Assign menu command, the submenu applicable to the type of object, and the desired assignment option. Table 7-2 identifies the forms generated when the various commands are used.
TABLE 7-2 Input Forms for Load Commands on the Assign Menu Command Joint/Point Loads > Force Ground Displacement Temperature Name of Input Form* Point Forces Ground Displacements Point Temperatures
7-4
Chapter 7 - Load the Structural Model
TABLE 7-2 Input Forms for Load Commands on the Assign Menu Command Frame/Line Loads > Point Distributed Temperature Open Structure Wind Parameters Shell/Area Loads > Uniform Temperature Wind Pressure Coefficient Name of Input Form* Frame Point Loads Frame Distributed Loads Line Object Temperatures Auto Wind Load Overwrites Uniform Surface Loads Area Object Temperatures Wind Pressure Coefficients
* Note: With a form displayed on the ETABS window, click the F1 key on your keyboard to access context-sensitive Help for the form.
Although the form names vary depending on the command used, each form has a drop-down list that allows the user to select the load case to be assigned. Logically, the available load cases vary depending on the type of assignment. The forms also include other object/assignmentspecific input fields that enable the user to refine the load assignment. Search for static loads using the Help menu > Search for Help on command for more information about the load commands.
7-5
Chapter 8 8
Assign/Change Properties
Objective
This chapter describes how to assign or change the properties of structural objects in the model.
Properties
In creating the model, the user draws point, line, and area objects. To enable analysis and design, those objects must be assigned properties, such as material properties, frame sections, wall/slab/deck sections, link properties, and loads, among others. Note that the assign menu lists the various properties that can be assigned. Also note that the assignment of loads was explained in Chapter 7 of this guide. As shown in Table 8-1, the types of assignments available depend on the type of object. Assignments also depend on the type of design (e.g., steel versus concrete versus composite design).
Objective
8-1
User's Guide
TABLE 8-1 Possible Assignments to Objects by Object Type

Object Joint/Points Assignment Option Diaphragms Panel Zones Restraints (Supports) Point Springs Link Properties Additional Point Masses Frame Sections Frame Releases/Partial Fixity Moment Frame Beam Type End (Length) Offsets Insertion Point Frame Output Stations Local Axes Frame Property Modifiers Tension/Compression Limits Link Properties Frame NonLinear Hinges Pier Label Spandrel Label Line Springs Additional Line Masses Automatic Frame Subdivide Use Line for Floor Meshing Wall/Slab/Deck Sections Openings Diaphragms Local Axes Shell Stiffness Modifiers Pier Label Spandrel Label Area Springs Additional Area Masses Area Object Mesh Options Auto Line Constraint Name of Input Form* Assign Diaphragm Assign Panel Zone Assign Restraints Assign Springs Assign NLLink Properties Assign Masses Assign Frame Properties Assign Frame Releases Special Moment Beams Frame End Length Offsets Frame Insertion Point Assign Output Station Spacing Axis Orientation Analysis Property Modification Factors Frame T/C Limits Assign NLLink Properties Assign Frame Hinges (Pushover) Pier Names Spandrel Names Assign Spring Assign Mass Line Object Auto Mesh Options **Yes, No, Cancel Assign Wall/Slab/Deck Sections Assign Openings Assign Diaphragm Assign Local Axis Analysis Stiffness Modification Factors Pier Names Spandrel Names Assign Spring Assign Mass Area Object Auto Mesh Options Auto Line Constraint Options
Frame/Lines
Shell/Areas
* Note: With a form displayed on the ETABS window, click the F1 key on your keyboard to access context-sensitive Help for the form. **Not a form; possible input parameters
8-2
Properties
Chapter 8 - Assign/Change Properties View the assignments made to point, line, and area objects by right clicking on the object. The appropriate Point Information, Line Information, or Area Information form will display. Click on the Assignments tab. In each case, select an object before executing the desired assignment command (e.g., select a line object before using the Assign menu > Frame/Lines > Frame Sections command). As explained in Chapter 6 of this guide, using the Ctrl key and left clicking on a location in the model can simplify the process of selecting objects when multiple objects may be present at the same location or if selecting objects is new to the user and seems challenging. The availability of commands depends on the type of object selected. The input forms include object/assignment-specific input fields that enable refinement of the assignment. Modifications to the assignments can be made by accessing the input forms using the appropriate Assign menu command. The forms include OK and Cancel buttons that can be used to accept or delete changes made to the forms. Note that the combination of the type of object, name of the command and name of the input form provides an indication of what can be achieved by using a particular command.
Auto Select Section List

ETABS's Auto Select Section List feature helps to control the time required to develop the model as well as to enhance the design process. An auto select selection list is simply a list of sections; for example, W18X35, W18X40, W21X44, W21X50 and W24X55. Auto select section lists can be assigned to frame members. When an auto select selection list is assigned to a frame member, the program can automatically select the most economical, adequate section from the auto select section list when it is designing the member. The program has several built-in auto select section lists. However, the user can also develop a tailored list using the following steps:
8-3
User's Guide 1. Click the Define menu > Frame Sections command, which will display the Define Frame Properties form shown in Figure 8-1.
Figure 8-1: The Define Frame Properties form
2. Click the drop-down list that reads "Add I/Wide Flange" in the Click to area of the Define Frame Properties form. Scroll down the resulting list of potential Add sections to locate Add Auto Select List. Click on it. The Auto Selection Sections form shown in Figure 8-2 displays. 3. Type a name for the list in the Auto Section Name edit box. Any name can be used. For the purposes of this description, the new Auto Select Section List is AUTOLATBM. 4. Scroll down the list of beam sections in the List of Sections to find the beams to be included in the list. Click once on them to highlight them. Note that the standard Windows methods for selecting items in a list can be used (e.g., clicking on a beam and then pressing the shift key on the key board before selecting another beam will highlight all beams between the two selected beams).
8-4
Chapter 8 - Assign/Change Properties
Figure 8-2: Auto Select Sections form
5. Click the Add button to add the selected beams to the Auto Selections list on the right side of the form. 6. Click the OK button and then click the OK button in the Define Frame Properties form to accept the definition of a new Auto Select Section List named AUTOLATBM.
Assign the AUTOLATBM Auto Select Section List

The AUTOLATBM Auto Select Section list created as described in the previous section consists of various sections that can be assigned to a line object. Thus, in making the assignment, the user should not select a point or area object in the model, or click the Joint/Point or Shell/Area commands on the Assign menu. Rather, the user should select a frame/line object (e.g., a beam) and then click the Assign menu > Frame/Line > Frame Section command or the Assign Frame Section button, . This will access the Assign Frame
8-5
User's Guide Properties form. In the Properties area of that form, scroll down the list of properties to locate and highlight the name of the Auto Select Section List to be assigned; AUTOLATBM in this example. Note that when a name is highlighted in the list, the name also appears in the edit box at the top of the list. Click the OK button and the assignment of the Auto Select Section List named AUTOLATBM is complete.
Make an Assignment as the Object is Drawn
An Auto Select Section List can also be assigned when the frame/line object is being drawn on the model. Using this method, select the desired Auto Select Section list by name from the Property drop-down list in the Properties of Object Box that appears when a drawing tool is selected. Use of the drawing tools is described in Chapter 5 of this guide along with figures showing the Properties of Object boxes for point, line, and area objects.
Check the Sections in an Auto Select Section List

As indicated previously, several Auto Select Section Lists are built into the program. To review the sections included in any Auto Select Section Lists, whether built in or user-specified, complete the following steps: 1. Click the Define menu > Frame Sections command or click the . The Define Frame Properties Define Frame Sections button form will display. 2. Highlight the name of the Auto Select Section List to be checked in the Properties drop-down list. 3. Click the Modify/Show Property button. The Auto Selection Sections form displays; the sections included in the selected auto select section list are listed in the Auto Selections area of the form, available for review. 4. Click the Cancel button to close the form.
8-6
Chapter 9
Edit the Model Geometry

Objective
This chapter describes how to edit the model quickly and easily while maintaining model integrity.
Editing Options
During the course of creating the model, the model may require editing. Table 9-1 identifies the various edit commands available in the program. Some are familiar Windows commands. In most cases, first select the point, line, or area object, then click the appropriate menu or button. In some cases, the action will be immediate (e.g., the Undo or Redo commands). In other cases, a form will display that allows the user to specify how the object is to be edited (e.g., the Edit menu > Align Points/Lines/Edges command accesses the Align Selected Lines/Edges/Points form, which allows the user to align points to the x, y, z coordinate or to the nearest point, or to trim or extend lines). Objective 9-1
User's Guide In other cases, the command is a toggle that, when enabled, will affect subsequent actions. Note that the type of commands and options available depend on the type of object being edited.
TABLE 9-1 Edit Commands in ETABS
Command Undo and Redo Undo Redo Action deletes the last performed action. restores the last step that was unImmediate Immediate/ Form* Used/ Toggle Immediate
done. Cut, Copy and Paste Generally similar to the standard cut, copy and paste Windows commands, with some ETABS specific behaviors. Only active in plan or plan perspective view. Delete Delete deletes the selected object(s) and all Immediate
of its assignments (loads, properties, supports and the like). Add to Model from Template Adds two-dimensional and three-dimensional frames to the model. 2-D or 3-D Template Forms that access other forms Replicate Replicate replicates one or more objects Replicate Form that accesses options form Coordinate Systems Form that accesses definition forms and most of the object's assignments. Note that replicated objects will not replace objects already placed at a location. Edit Grid Data > Edit Grid Edit Grid edits the coordinate system. Resulting form allows user to select a previously defined grid system; define a new system; add a copy of an existing system; show/modify an existing system; and delete an existing system. > Add Grid at Selected Points Adds grid lines at selected points. Add Grid Lines at Selected Point Form
9-2
Editing Options
Chapter 9 - Edit the Model Geometry

Command > Glue Points to Grid Lines Action "Glues" point objects that lie directly on grid lines to those grid lines. When a point object is glued to a grid line and the grid line is moved, the point object moves with the grid line. Line and area objects that are attached to the point object when it is moved remain attached to the point object and move or resize as appropriate. > Lock OnScreen Grid System Edit Edit Story Data > Edit Story Edit Story allows changes to story labels, Story Data Form heights, master story designation, Similar To designation, splice point and splice height. Allows changes to base story elevation. > Insert Story Inserts new story into the model. Allows the user to define story name, story height, number of stories to insert, location/placement of inserted story(ies) and if the story is to replicate from another story (i.e., be a copy of another story, including properties). > Delete Story Edit Reference Planes Allows user to select and delete a story from the model. Allows the user to create, modify and delete reference planes. Reference planes are horizontal planes at user-specified Z-ordinates. Reference planes provide a horizontal plane that can be used when drawing objects in elevation views to snap objects into place (for more information search for snap to using the Help menu). Select Story to Delete Form Edit Reference Planes Form Insert New Story Form Allows users to lock out the ability to move grid lines graphically on-screen using the Reshape Object command. Toggle Immediate/ Form* Used/ Toggle Toggle
Editing Options
9-3
User's Guide

Command Edit Reference Lines Action Allows the user to create, modify and delete reference lines. Reference lines are vertical lines at user-specified global X and Y coordinates. Reference lines can be used when drawing objects in elevation or plan views to snap objects into place (for more information search for snap to Immediate/ Form* Used/ Toggle Edit Reference Lines Form
using the Help menu) . Merge Points Merge Points merges points within a userMerge Selected Points Form
specified tolerance distance of the selected Align Points/Lines/ Edges point. Align Points/Lines/Edges helps the user
Align Selected Lines/Edges/ Points Form
align objects in the model. Search for edit points lines edges using the Help menu > Search for Help on command for important notes about using this command. Move Points/Lines/ Areas Move Points/Lines/Areas helps the user
Move Points/Lines/ Areas Form
move objects in the model. Search for move points lines edges using the Help menu > Search for Help on command for more information.
Expand/Shrink Areas
Expand/Shrink Areas Merge Areas
expands or shrinks an
Expand/Shrink Areas Form Immediate Can use Undo
area object using a user-specified offset value. Merge Areas merges two area objects that
have a common edge or overlap into one area object. Mesh Areas Mesh Areas divides selected areas into
Mesh Selected Areas Form
additional objects using user-specified options. Search for mesh using the Help menu > Search for Help on command for more information. Split Area Edges Adds point objects at the mid-point of each edge of an area object.
Immediate Can use Undo
9-4
Editing Options
Chapter 9 - Edit the Model Geometry

Command Join Lines Join Lines Action joins two or more collinear line Immediate/ Form* Used/ Toggle Immediate Can use Undo
objects with common end points and the same type of property into a single line object. Divide Lines Divide Lines ple line objects. Extrude Point to Lines Creates line objects from points. Options are available for linear or radial extrusion. This feature is especially suited to creating beams/columns from point/nodes. Extrude Lines to Areas Extrude Lines to Areas creates area objects divides a line object into multi-
Divide Selected Lines Form Extrude Point to Lines Form
Extrude Lines to Areas Form
from lines. Options are available for linear or radial extrusion. This feature is especially suited to creating area objects from beams. Auto Relabel All Relabels all objects of the current model. Command cannot be undone. Use this command after model creation is complete to get optimum labeling for the model. Nudge Works with Ctrl and arrow keys to move objects. Allows the user to select objects and move them a predefined distance. For more information, search for nudge using the Help menu.
Warning message Cannot use Undo Immediate
Editing Options
9-5
Chapter 10
10
Analyze the Model

Objective
This chapter describes how to analyze the model.
Model Analysis
To run the analysis, click the Analyze menu > Run Analysis command or the Run Analysis button, . The program will display an "Analyzing, Please Wait" window. Data will scroll in this window as the program runs the analysis. After the analysis has been completed, the program performs a few more bookkeeping actions that are evident on the status bar in the bottom left-hand corner of the ETABS window.
Objective
10 - 1
User's Guide
Locking and Unlocking the Model

When the entire analysis process has been completed, the model automatically displays a deformed shape view of the model, and the model is locked. The model is locked when the Lock/Unlock Model button, , appears depressed. Locking the model prevents any changes to the model that would invalidate the analysis results.
10
10 - 2
Locking and Unlocking the Model
Chapter 11
11
Design
Objective
This chapter describes design using the ETABS design postprocessors.
Design the Structure

The ETABS design postprocessors include the following:

Steel Frame Design Concrete Frame Design Composite Beam Design Steel Joist Design Shear Wall Design
Objective
11 - 1
User's Guide To perform the design, first run the analysis (described in Chapter 10), then click the Design menu and select the appropriate design from the drop-down menu. The type of design available depends on the type of members used in the model. That is, the user cannot complete a shear wall design if no shear walls have been included in the model. Similarly, the commands used to execute a design depend on the type of design to be performed. However, each design has commands to address the following:

Review and/or select design combinations. Review and/or select overwrites. Start the design or check of the structure. Perform interactive design. Display input and output design information on the model.
11
Generally, the sequence for using commands is indicated by their availability. In other words, some commands must be used before other commands become available. This helps the user step through the design process. (Search for process using the Help menu to access more information about design processes and the sequence of commands.) Table 11-1 identifies the commands that are used to start design depending on the desired design process.
TABLE 11-1 Start Design Commands Design Process Steel Frame Design Concrete Frame Design Composite Beam Design Command that Starts Design Start Design/Check of Structure Start Design/Check of Structure Start Design using Similarity or Start Design Without Similarity Start Design using Similarity or Start Design Without Similarity Start Design/Check of Structure
Steel Joist Design Shear Wall Design
11 - 2
Chapter 11 - Design It is important to understand that design in ETABS is an iterative process. That is, the user should run the analysis and then perform the design and be prepared to run the analysis again and perform the design again. It may be necessary to repeat this process several times before the design is complete. The objective is to have the analysis sections match the design sections. The program will report any differences. The user should repeat the analysis/start design process until the analysis and design sections match (i.e., the program does not display an error message). Tables 11-2 through 11-6 summarize the commands used in each type of design process.
Note: With a form displayed in the ETABS window, click the F1 key on your keyboard to access context-sensitive Help for the form. TABLE 11-2 Steel Frame Design Commands Command
Select Design Group
11
Action
Designates that a group is to be used as a design group. Works only when auto select sections have been assigned to frame objects. All frame objects in the group will be given the same design section.
Form
Steel Frame Design Group Selection Form
Select Design Combo
Allows review of the default steel frame design combinations defined by the program, or designation of user-specified design combinations. Facilitates review or modification of combinations during design.
Design Load Combinations Selection Form
View/Review Overwrites
Allows review of overwrites, which are parameters that the user specifies to change program defaults. Overwrites apply only to the frame objects to which they are specifically assigned.
Overwrites Form
Set Lateral Displacement Targets Set Time Period Targets
Specifies displacement targets, in any direction, for various load cases. Specifies time period targets for seismic analysis.
Lateral Displacement Targets Form Time Period Targets Form
11 - 3
User's Guide
TABLE 11-2 Steel Frame Design Commands Command

Start Design/Check of Structure
Action
Initiates design process. If frame objects have been selected before this command is clicked, only the selected frame objects will be designed. A building analysis must precede use of this command.
Form
Immediate, no form used
Interactive Steel Frame Design
Allows the user to review the design results for any frame object and then to interactively change the design overwrites and immediately view the results.
No form; results are displayed onscreen. Display Design Results Form
11
Display Design Info
Allows review of some of the results of the steel frame design directly on the program model. Examples of results that can be displayed include design sections, unbraced lengths, effective length factors, allowable stresses, and stress ratio information.
Make Auto Select Section Null
Removes auto select section lists from selected frame objects. Typically used near the end of the iterative design process so that the final design iteration is performed using the actual frame sections assigned, not auto select sections. Only works on a user-specified selection.
Warning message Cannot use Undo
Change Design Section
Allows the user to change the design section property assigned to one or more frame objects and then rerun the design without first rerunning the analysis. Only works on a user-specified selection.
Select Sections Form
Reset Design Section to Last Analysis Verify Analysis vs Design Section
Sets the design section for one or more frame objects back to the last used analysis section. Only works on a user-specified selection. Verifies that the last used analysis section and the current design section are the same for all steel frame objects in the model.
Immediate Cannot use Undo Immediate
11 - 4
Chapter 11 - Design
TABLE 11-2 Steel Frame Design Commands Command

Verify All Members Passed
Action
Reports if structural members have passed the stress/capacity check. An analysis and a design/check of the structure must be completed before this command is used.
Form
Immediate
Reset All Steel Overwrites Delete Steel Design Results
Resets the overwrites for all frame objects with the Steel Frame design procedure to their default values. Deletes all of the steel frame design results but not the current design section (i.e., next analysis section).
Warning message Cannot use Undo Immediate Cannot use Undo
11
Action Form
TABLE 11-3 Concrete Frame Design Commands Command

Select Design Combo
Allows review of the default concrete frame design combinations defined by the program, or designation of user-specified design combinations. Facilitates review or modification of combinations during design.
Allows review of overwrites, which are parameters that the user specifies to change program defaults. Overwrites apply only to the frame objects to which they are specifically assigned.
Overwrites Form
Start Design/Check of Structure
Initiates design process. If frame objects have been selected before this command is used, only the selected frame objects will be designed. A building analysis must precede use of this command.
Interactive Concrete Frame Design
Allows the user to review the design results for any frame object and then to interactively change the design overwrites and immediately view the results.
No form; results are displayed onscreen.
11 - 5
User's Guide
TABLE 11-3 Concrete Frame Design Commands Command

Display Design Info
Action
Allows review of some of the results of the concrete frame design directly on the program model. Examples of results that can be displayed include design sections, unbraced lengths and longitudinal reinforcing.
Form
Display Design Results Form
Allows the user to change the design section property assigned to one or more frame objects and then rerun the design without first rerunning the analysis. Only works on a user-specified se-
11
lection. Reset Design Section to Last Analysis Verify Analysis vs Design Section Reset All Concrete Overwrites Delete Concrete Design Results Sets the design section for one or more frame objects back to the last used analysis section. Only works on a user-specified selection. Verifies that the last used analysis section and the current design section are the same for all concrete frame objects in the model. Resets the overwrites for all frame objects with the Concrete Frame design procedure to their default values. Deletes all of the concrete frame design results but not the current design section (i.e., next analysis section). Immediate Cannot use Undo Warning message Cannot use Undo Immediate Immediate Cannot use Undo
TABLE 11-4 Composite Beam Design Commands Command

Select Design Group
Action
Designates that a group is to be used as a design group. Works only when auto select sections have been assigned to frame objects. When grouped, all beams in the group are given the same beam size, but the shear connectors and camber may be different.
Form
Composite Design Group Selection Form
11 - 6
Chapter 11 - Design

Select Design Combo
Action
Allows review of the default composite frame design combinations defined by the program, or designation of user-specified design combinations. Facilitates review or modification of combinations during design. Note that separate design combinations are specified for construction loading, final loading considering strength, and final loading considering deflection.
Form
Allows review of overwrites, which are parameters that the user specifies to change program defaults. Overwrites apply only to the composite beams to which they are specifically assigned.
Overwrites Form
11
Start Design using Similarity
Assumes that if a composite beam is located at a story designated as similar to a master story, that composite beam has the same composite beam size as the composite beams of the master story (set a story Similar To a master story in the Story Data; see the Edit menu > Edit Story Data > Edit Story command).
Start Design without Similarity
Excludes the similarity features described in the description of the Start Design using Similarity command. ALWAYS use this command for final design.
Interactive Composite Beam Design
Allows the user to review the design results for any composite beam and then to interactively change the design overwrites and immediately view the results.
Display Design Info
Allows review of some of the results of the composite beam design directly on the program model. Examples of results that can be displayed include beam labels and associated design group names; design sections together with connector layout, camber and end reactions; and stress ratio information.
11 - 7
User's Guide

Action
Removes auto select section lists from selected beams. Typically used near the end of the iterative design process so that the final design iteration is performed using the actual beam sections assigned, not auto select sections. Only works on a user-specified selection.
Form
Allows the user to change the design section property assigned to one or more beams and then rerun the design without first rerunning the analysis. Only works on a user-specified selection.
11
Reset Design Section to Last Analysis Verify Analysis vs Design Section Verify All Members Passed
Sets the design section for one or more beams back to the last used analysis section. Only works on a user-specified selection. Verifies that the last used analysis section and the current design section are the same for all composite beams in the model. Reports if structural members have passed the stress/capacity check. An analysis and a design/check of the structure must be completed before this command is used.
Immediate Cannot use Undo Immediate
Immediate
Reset All Composite Beam Overwrites Delete Composite Beam Results
Resets the overwrites for all composite beams with the Composite Beam design procedure to their default values. Deletes all of the composite beam design results but not the current design section (i.e., next analysis section).
TABLE 11-5 Steel Joist Design Commands Command

Select Design Group
Action
Designates that a group is to be used as a design group. Works only when auto select sections have been assigned to the joists. When grouped, all objects in the group are given the same joist size.
Form
Composite Design Group Selection Form
11 - 8
Chapter 11 - Design

Select Design Combo
Action
Allows review of the default steel joist design combinations defined by the program, or designation of user-specified design combinations. Facilitates review or modification of combinations during design.
Form
Allows review of overwrites, which are parameters that the user specifies to change program defaults. Overwrites apply only to the steel joists to which they are specifically assigned.
Overwrites Form
Start Design using Similarity
Assumes that if a steel joist is located at a story designated as similar to a master story, that steel joist has the same joist size as the steel joists of the master story (set a story Similar To a master story in the Story Data; see the Edit menu > Edit Story Data > Edit Story command).
11
Start Design Without Similarity
Excludes the similarity features described in the description of the Start Design using Similarity command. ALWAYS use this command for final design.
Interactive Steel Joist Design
Allows the user to review the design results for any steel joist and then to interactively change the design overwrites and immediately view the results.
Display Design Info
Allows review of some of the results of the steel joist design directly on the program model. Examples of results that can be displayed include joist labels and associated design group names; design sections together with end reactions; and design ratio information.
Removes auto select section lists from selected joists. Typically used near the end of the iterative design process so that the final design iteration is performed using the actual joist sections assigned, not auto select sections. Only works on a user-specified selection.
11 - 9
User's Guide

Action
Allows the user to change the design section property assigned to one or more joists and then rerun the design without first rerunning the analysis. Only works on a user-specified selection.
Form
Verify Analysis vs Design Section Verify All Members Passed
Verifies that the last used analysis section and the current design section are the same for all steel joists in the model. Reports if all steel joists have passed the stress/capacity check. An analysis and a design/check of the structure must be completed before this command is used.
Immediate
Immediate
11
Reset All Steel Joist Overwrites Delete Steel Joist Results
Resets the overwrites for all steel joists with the Steel Joist design procedure to their default values. Deletes all of the steel joist design results but not the current design section (i.e., next analysis section).
TABLE 11-6 Shear Wall Design Commands Command

Select Design Combo
Action
Allows review of the default shear wall design combinations defined by the program, or designation of user-specified design combinations. Facilitates review or modification of combinations during design.
Form
View/Review Pier Overwrites
Allows review of pier overwrites, which are parameters that the user specifies to change program defaults. Overwrites apply only to the piers to which they are specifically assigned.
Overwrites Form
View/Review Spandrel Overwrites
Allows review of spandrel overwrites, which are parameters that the user specifies to change program defaults. Overwrites apply only to the spandrels to which they are specifically assigned.
Overwrites Form
11 - 10
Chapter 11 - Design
TABLE 11-6 Shear Wall Design Commands Command

Define Pier Sections for Checking Assign Pier Sections for Checking Start Design/Check of Structure
Action
Allows the user to define a pier section using the Section Designer utility. Allows the user to assign a pier one of three section types. Initiates design process. If piers or spandrels have been selected before this command is used, only the selected piers or spandrels will be designed. A building analysis must precede use of this command.
Form
Define General Pier Sections Form Assign Pier Sections Form Immediate, no form used
Interactive Wall Design
Allows the user to review the design results for any piers or spandrels and then to interactively change the design overwrites and immediately view the results.
11
Display Design Info
Allows review of some of the results of the shear wall design directly on the program model. Examples of results that can be displayed include reinforcing requirements, capacity ratios and boundary element requirements.
Reset All Pier/ Spandrel Overwrites Delete Wall Design Results
Resets the overwrites for all piers or spandrels to their default values. Deletes all of the shear wall results.
11 - 11
Chapter 12
12
Graphical Displays
Objective
This chapter describes how to display analysis results graphically.
Obtain Basic Graphical Displays

Analysis results can be displayed graphically after the analysis has been run. To display results, click the Display menu and select the type of display desired. Table 12-1 identifies the display options.
Objective
12 - 1
User's Guide
TABLE 12-1 Display Menu Options Command

Show Undeformed Shape Show Loads > Joint/Point > Frame/Line > Shell/Area Show Deformed Shape Displays loads assigned to Points. Displays loads assigned to Lines. Displays loads assigned to Areas. Show Deformed Shape plots a deformed Show Joint/Point Loads Form Show Frame/Line Loads Form Show Shell/Area Loads Form Deformed Shape Form Mode Shape Form
Action
Show Undeformed Shape formed shape onscreen. plots the unde-
Form*
No form; results are displayed.
12
Show Mode Shape Show Member Forces/ Stress Diagram > Support/Spring Reactions > Frame/Pier/ Spandrel Forces > Shell Stresses/ Forces
shape onscreen based on user-specified loads. This plot can be animated. Show Mode Shape plots a deformed shape onscreen based on user-specified modes. This plot can be animated.
Displays support and spring reactions onscreen based on user-specified loads. Displays column, beam, brace, pier and spandrel forces onscreen based on user-specified loads. Displays internal shell element forces and stresses onscreen based on user-specified loads.
Point Reaction Forces Form Member Force Diagram for Frames Form Element Force/Stress Contours for Shells Form Member Force Diagram Form Energy/Virtual Work Diagram Form
> Link Forces Show Energy/Virtual Work Diagram
Displays link forces onscreen based on userspecified loads. Show Energy/Virtual Work Diagram dis-
plays energy/virtual work diagrams that can be used as an aid to determine which elements should be stiffened to most efficiently control the lateral displacements of the structure. User defines forces and displacements
12 - 2
Chapter 12 - Graphical Displays
TABLE 12-1 Display Menu Options Command

Show Response Spectrum Curves Show Time History Traces
Action
Show Response Spectrum Curves plots various response spectra after a time history analysis has been run. Show Time History Traces plots various
Form*
Response Spectrum Generation Form Time History Display Definition Form Pushover Curve Form
time history curves based on user-specified data after a time history analysis has been run.
Show Static Pushover Curve
Show Static Pushover Curve
displays
various pushover curves based on user specified data after a static nonlinear analysis has been run.
Show Story Response Plots
Show Story Response Plots displays force and displacement responses under lateral loads for specified stories.
Story Forces/Response for Lateral Loads Form Choose Tables for Display Form
12
Show Tables
Show Tables Mode allows the user to select the type of information to display in table format.
12 - 3
Chapter 13
Generate Results
Objective
This chapter describes how to generate analysis and design results that can be printed to a printer or to a file for sharing with other programs.
13
Analysis and Design Results

Analysis and design results can be printed to a printer or a file using the File menu commands. Table 13-1 identifies the print commands.
Objective
13 - 1
User's Guide
TABLE 13-1 File Menu Print Options Command

Print Setup Print Preview for Graphics Print Graphics
Action
Allows the user to specify the paper size and orientation of the page. Provides a snap shot of how the file will print in graphical format. Print Graphics prints whatever graphics
Form*
Print Setup Form N/A N/A
are displayed in the active window to the printer that is currently specified as active. Print Tables > Input > Analysis Output Prints tables of analysis input data to a printer or to a text file. Prints tables of analysis output data to a printer or to a text file. > Summary Report > Print Design Tables Prints a summary report of model data to a printer or to a text file. Prints tables of design output data to a printer or to a text file based on which design was used in the model and the design the user selects when this command is used: Steel Frame, Concrete Frame, Composite Beam, Steel Joist, or Shear Wall. Print Input Tables Form Print Output Tables Form Print Summary Report Form Print Design Tables Form
13
13 - 2
Analysis and Design Results

Etabs User PDF

Uploaded by

Copyright:

Available Formats

Etabs User PDF

Uploaded by

Document Information

Original Title

Copyright

Available Formats

Share this document

Share or Embed Document

Sharing Options

Did you find this document useful?

Is this content inappropriate?

Copyright:

Available Formats

Etabs User PDF

Uploaded by

Copyright:

Available Formats

ETABS

Integrated Building Design Software

Computers and Structures, Inc. Berkeley, California, USA

Version 9 November 2005

Analyze Display Design Preferences

2-7 2-7 2-8 2-8

Basic Modes, Drawing Tools, Mouse Pointers

Create the Structural Model

Select Structural Objects

Get Previous Selection Command Clear Selection Command

Load the Structural Model

Edit the Model Geometry

Analyze the Model

Users Guide 11 Design

Chapter 1 - Program Description

Time Saving Options

Templates and Defaults

Time Saving Options

The ETABS Window

Toolbars Main Title Bar

Display Title Bar (Active Window)

Mouse Pointer Position Coordinates Status Bar

Figure 2-1: The ETABS graphical user interface

The ETABS Window

The ETABS Window

The Aerial View

Chapter 2 - ETABS Screen

Figure 2-2: Example of the aerial view

Basic Modes, Drawing Tools, Mouse Pointers

Draw Point Objects Draw Line Objects

Draw Area Objects

Draw Developed Elevation Definition

Create the Basic Grid System

Figure 4-1 The New Model Initialization form

Create the Basic Grid System

Chapter 4 - Begin a Model

Grid Dimensions (Plan) - Define a Grid System

Create the Basic Grid System

Create the Structural Model

Define Story Data

Add Structural Objects Using Templates

Add Structural Objects Using Templates

Add Structural Objects Using Templates

Display Title Bar (active)

Figure 5-1 The ETABS main window

Add Structural Objects Manually

Chapter 5 - Create the Structural Model

Figure 5-2 Properties of Object Box for Columns

Add Structural Objects Manually

Figure 5-3 Drawing Column Objects in a Windowed Region

Figure 5-4 Properties of Object Box for Beams

Add Structural Objects Manually

Draw Secondary (Infill) Beams

Draw the Floor

Add Structural Objects Manually

Figure 5-5 Properties of Object Box for Areas

Add Structural Objects Manually

Chapter 5 - Create the Structural Model

Figure 5-6 Set Building View Options form