• What does “Global” in the lower right-hand drop-down list refer to?

It refers to the coordinate system being used with the current display. Users can have multiple coordinate systems associated with the same model, cartesian and/or cylindrical. When more than one coordinate system has been defined, users can switch between them using the drop-down list in the bottom right corner of the SAP2000 screen which usually defaults to “Global”.

• How do I change the display colors?

Go to the Options > Colors command, and click on either the Display or Output tab and select new colors.

• Can I change the units used at any time?

You may change the units at any time, either by clicking on the drop-down list in the lower right-hand corner, or on individual forms where it is an option. In addition, no matter which units you are working with, you can use ‘ or “ to indicate feet and inches when working in architectural units, and the software will automatically convert them. Also, you can utilize other designations such as plf (pounds per lineal foot), psi (pounds per square inch), mph (miles per hour), in (inches), N (Newtons), etc. and the program automatically accepts and converts those units. Please note that the file will always be saved in the units shown when the model is started.

• How do I control which buttons are displayed on the toolbars?

Click on an arrow pointing down along the top toolbar, or on an arrow pointing to the left on the side toolbar, to change, add or delete the buttons shown.

• Can I move the buttons on the toolbar?

Sure – simply grab a group of buttons by their handle (denoted by the double lines) and drag them to a different toolbar location, or off the toolbar completely.

• How do I set the display so that only one view is shown?

Go to the Options > Windows > One command. The program can display anywhere from one to four views.

• I want to create my model from scratch without using any templates — should I still define a grid?

As a general rule, yes! A well thought out grid system will greatly enhance speed and accuracy when drawing the model, and will provide more options when viewing (planar views are automatically available at each grid line). It’s usually faster to draw frame and shell/area objects snapping to grids. Double click a grid at any time to modify, add, or delete grids.

• I accidentally selected the wrong object — how do I unselect it?

Simply click on the same object once again to unselect it, or hit the ‘clr’ (clear selection) button to unselect all. Note that right next to the clear selection button, there are two other related buttons which are commonly used: ‘ps’ for previous selection is useful when making multiple assignments to the same group without having to manually select them each time, and the’ all’ button selects the entire model including all joints, areas and lines.

• Can more than one object be selected at a time?

Sure – you may simultaneously select every object in the model, if so desired. Please note that after selecting, in the bottom left corner of the screen you can see the number of points, lines, areas, and edges selected.

• How do I display the local axes for frame objects?

Go to the View > Set Building View Options command and mark the Local Axes checkbox under the Frames/Cables/Tendons section and you will see Red, White and Blue arrows appear, which correspond to axes 1, 2, and 3 respectively. A helpful way to remember this is to think of the colors of the American flag: Red, White, and Blue = axes 1, 2, and 3. Please note that this ‘Set Building View’ dialogue is used to display local axes not only for frame objects, but also for joints, area shells/plates, and links.

• How do I change the local 1 axis direction on a frame member?

First, select the member by clicking on it with the Select button active. Next, go to the Assign > Frames/Cables/Tendons > Reverse Connectivity command – this reverses the I and J joint assignments for this member and hence, the direction of the local 1 axis (this also affects the other local axes as defined by the right-hand rule).

• How do I change the local 2-3 axes direction on a frame member?

First, select the member by clicking on it with the Select button active. Next, go to the Assign > Frames/Cables/Tendons > Local Axes command and specify the angle by which the 2-3 axes should be rotated.

• How do I draw a spring between two joints?

First Define > Link/Support Properties for Linear type and input spring stiffness. Then go to the Draw > Draw 2 Joint Link command and click on each joint.

• How do I draw a triangular area object?

Go to the Draw > Draw Poly Area command and click at each of the three corners, and click a fourth time on the initial joint.

• What is the difference between an object and an element?

Objects are what the user draws in the SAP2000 interface, and are intended to represent physical members. Internally, objects are mathematically modeled in the program using elements, or finite elements. Each object will consist of one or more elements. At analysis time, the program automatically converts (meshes) the object-based model into an element-based model, and when the analysis is complete, converts the results back for display at the object level.

• How do I change from a roller support to a pinned support?

Select the joint where the support is located, and go to the Assign > Joint > Restraints command and click on the pinned button.

• Is there an easy way to revise the grid?

Sure – go to the Define > Coordinate Systems/Grids command, select the grid to be altered, and click on the Modify/Show System button. On the Define Grid Data form, you may change the ordinates of the grids as well as delete and add grids. Also, you can double click grids at any time to go into the Define Grid data form.

• How do I make sure that a frame object being drawn is vertical?

After selecting the Draw Frame button, click on the location of the starting point of the member (this should be done in a planar view). Next, go to the Properties of Object box and in the Drawing Control Type drop-down list, select Vertical and then click on the ending point.

• How do I change the length of a frame object?

Right click on the joint at the end of the member you wish to change, and in the Point Information form edit the coordinates – all objects connected to this point will remain connected when it moves

• How do I draw a solid object?

Solid objects are generated by extruding area objects. Draw and mesh area objects that represents one face of the solid object, and then select these objects and go to the Edit > Extrude > Extrude Areas to Solids command. On the Extrude Areas to Solids form there are a number of different options for the generation of solid objects – make sure to check the Delete Source Objects box if you do not want the area objects to remain after generating the solid objects. Note that solid objects are available only in the Plus and higher versions.

• Why do 2-D views sometimes show objects that are not on that plane?

If certain objects are very close together, the default clipping tolerance may be too large. To change this tolerance, go to the Options > Preferences > Dimensions/Tolerances command and on the Dimensions/Tolerances form revise the Auto Merge Tolerance value.

Caution: This length tolerance is also used to automatically merge joints.

• I have a large model with both frame and area objects – can I create a view with the frame objects hidden?

Sure – simply go to the View > Set Display Options command and on the form check the Frames Not in View box in the Frames/Cables/Tendons section.

• If I move a grid line, how do I make sure that my model moves with it?

On the Define Grid Data form, click the Glue to Grid Lines option. Then when a grid line is moved, objects attached to this grid line will move or stretch with it.

• How do I draw a joint separate from a line or area object?

Simply go to the Draw > Draw Special Joint command, or click on the Draw Special Joint button, and click anywhere in a planar view where you want to draw a joint. You can draw the joint using offsets from the floating properties box which draws the joint offset a user specified distance from wherever you click, or right click to modify coordinates of the special joints at any time. Use these joints to ‘connect the dots’ in drawing objects, to assign joint loads along the length of a frame, to assign a point load offset and constrained to the structure, or use to extrude joints into beams or columns at any location or angle.

• How do I change a frame member section property?

First, select the member by clicking on it with the Select button active. Next, go to the Assign > Frames/Cables/Tendons > Frames Section command and select the new section property. If you do not see the desired frame section in the property list on the left, you will have to ‘Import’ it using the Import pull-down if it’s a standard steel section (AISC and International steel section libraries available), or ‘Add’ it if it’s a concrete section, a nonstandard section of any material, a built-up section using section designer, nonprismatic, or auto-select list section.

• Can I mistakenly assign a frame property to an area object?

No. No matter what is selected, you can only make assignments to a particular type of element during each assignment. For example, if you select shells/areas, frames, and joints, then Assign > Frames/Cables/Tendons will assign only to Frames in that selection, not to the joints or areas.

• How do I create a nonprismatic frame section?

Go to the Define > Frame Sections command and in the Frame Properties form click on the Add I/Wide Flange drop-down list and scroll down and click on Add Nonprismatic. Next, click on the Add New Property button, and on the Nonprismatic Section Definition form you may define multiple segments for each member that vary linearly, parabolically, or cubically.

• How do I reduce the moment of inertia in a concrete beam for the effects of cracking?

Select the beam(s), and then go to the Assign > Frame > Property Modifiers command. On the Property/Stiffness Modification Factors form, you may specify a multiplication factor equal to or greater than zero for any of the section properties – 0 meaning this quantity will have zero value, and 1 meaning this quantity will have full value. 1 is the default setting. For example, if you wanted to reduce the major moment of inertia of the frame by 50% for cracking, you would simply type .5 in Moment of inertia M3 axis field. In addition, the Frame Property Modifiers can also be specified using Define > Frame sections using the ‘Set Modifiers’ button.

• How do I display the section names on the model?

Go to the View > Set Building View Options command and mark the Sections checkbox.

• Can I duplicate a material property definition?

Sure – go to the Edit > Interactive Database Editing command and check the box for Property Definitions and then click OK. On the next form, select Material Properties from the drop-down list, which results in all of the material properties being displayed. Here you can select any property (highlight the entire line by clicking on the line number), copy it, and then paste it into the table. Make sure to change the property name, otherwise it will be deleted when you apply it to the model.

• How do I define an automated lateral wind load?

Go to the Define > Load Cases command and on the Define Loads form enter a load name and select WIND from the Type drop-down list. Next, select a code choice from the Auto Lateral Load drop-down list, click the Add New Load button, and then click the Modify Lateral Load button. On the Wind Loading form, specify the exposure and coefficients required for your code wind loads.

• How can I apply a projected roof load on a beam?

Select the beam, and then go to the Assign > Frame Loads > Distributed command. On the Frame Distributed Loads form, select Z Projected from the Direction drop-down list and then specify your loads.

• What is the difference between a load case and an analysis case?

A load case represents a spatial distribution of loads acting upon the structure, while an analysis case defines how the load cases are to be applied, and how the structural response is to be calculated. For modal analysis and linear static loads, analysis cases are automatically generated. But for additional dynamic analysis, nonlinear analysis, eigen buckling, moving loads, and multi-step static cases, users have to manually add or modify analysis cases.

• How can I review the loads on a specific joint?

Right click on the joint in question, and on the Point Information form click on the Loads tab.

• Can automatic wind loads be applied to a lattice framework?

Select ASCE 7-02 as your Auto Lateral Load, and when specifying the properties for this loading, make sure to click on the Exposure from Frame and Area Objects option and click to include Frame Objects (Open Structure). This procedure automatically accounts for section properties and local axis relative to wind direction in each load case.

• Is there a way to convert one large area object into multiple smaller objects?

Yes – select the object by clicking on it with the Select button active and go to the Edit > Divide Areas command and select from any of the divide area options. It is important to note that this procedure is fundamentally different than meshing – meshing is internal to the object, while dividing creates additional objects. Dividing is useful when you need to create clearly defined areas and/or joints for openings, connections and load assignments.

• How do I make sure that an object is meshed according to my requirements?

First, select the object by clicking on it with the Select button active. Next, go to the Assign > Area > Automatic Area Mesh command and select from any of the meshing options.

• How do I make two adjacent walls of different heights behave contiguously?

Select the area object used to model the taller of the two walls, and go to the Assign > Area > Generate Edge Constraints command. On the Assign Edge Constraints form, select the Create Constraints Around Objects Edges option.

• What are edge constraints?

Also known as ‘Line’ constraint in ETABS, the auto line constraint automatically connects adjacent elements that do not share common joints, such as a coarsely meshed shear wall intersecting with a finely meshed floor slab. Instead of having to manually re-mesh areas/shells or frame elements to create shared mesh points on the adjacent elements, the auto line constraint ‘zips’ them together using displacement constraints. By default, the auto line constraint is turned on in ETABS, but turned off in SAP2000 (user can modify these defaults). For more information please see: http://www.csiberkeley.com/Tech_Info/Line%20Constraint.pdf.

• What does the warning message “lost 6.4 digits of accuracy” mean?

SAP2000 equation solutions are performed in double precision arithmetic, which allows for 15 significant figures. If you have global or local instability (e.g., a node that is not restrained), the solution will suffer a loss of accuracy. The program issues a warning if the loss is estimated to be above 6 digits, and will cease processing if the detected loss is above 11 digits.

• I would like to use the Draw Section Cut option under the Draw menu but it is not available — what should I do?

The Draw > Draw Section Cut command is only available after an analysis has been completed. In order to use this command, run an analysis, and display either a deformed shape or member forces.

• How do I request mode (eigen- or ritz-) shape extraction?

Go to the Display > Show Deformed Shape command and on the Deformed Shape form select your modal case from the Case/Combo drop-down list

• When I view results for beam members in the database tables, the results are not shown at the ends of the members?

That is correct. SAP2000 reports member forces at the ends of the physical member, which is determined by subtracting the distance used for the end offsets from the overall object length. You may verify the distances used for the member end offsets by right clicking on a beam member, and then clicking on the Assignments tab. You may specify end offsets through the Assign > Frame/Cable/Tendon > End (Length) Offsets command.

• I want to limit my beam sections to W18’s during steel design — can I do it?

Easy – first you will want to go to the Define > Frame Sections command, and choose Add Auto Select from the drop-down list. Click the Add New Property button, and on the Auto Selection Sections form select all of the sections you wish to be considered in the design (e.g., all of the W18’s) and add them to the Auto Selections list – make sure to use a name you will remember. This list is then assigned to your frame objects in the same manner as any other frame property. In the initial analysis, the program will use the median weight section, and when designing, will select from the list the least weight section that satisfies the design criteria. If the design and analysis section are not the same, you should repeat the process until they are.

• How do I tell the program which concrete design code to use?

Go to the Options > Preferences > Concrete Frame Design command and on the Concrete Frame Design Preferences form click on the Design Code Value drop-down list to select your code preference.

• Where do I specify the yield strength for concrete reinforcement?

Reinforcing yield strengths are specified under the Design Property Data section of the Material Property Data form, which is accessed by going to the Define > Materials command and selecting the concrete material.

• I am going to have SAP2000 perform a concrete frame design using the ACI 318-05 code — do I need to specify design load combinations?

No – the program will automatically generate design combinations based on your load case definitions. However, you should review these combinations by going to the Design > Concrete Frame Design > Select Design Combos command, selecting each design combo and clicking on the Show button.