Combinations

Form:  Define Response Combinations, Response Combination Data

1. Click the Define menu > Combinations command to access the Define Response Combinations form.

2. Use the following buttons on the form to complete the appropriate action.

• Add New Combo button

1. Click the Add New Combo button to display the Response Combination Data form and specify the combination type, the analysis case, and any scale factor to be applied to the response combination.

2. Use the default or type another name in the Response Combination Name edit box. Note that each load combination and load case must have a unique name. Also, the word Mode is reserved and can not be used for either a load case name or a load combination name.

3. Select the Combination Type:

• Linear Add.  All analysis case results are multiplied by their scale factor and added together. This Combo Type can be used for static loads.

• Envelope.  A max/min Envelope of the defined analysis cases is evaluated for each frame output segment and object joint. The analysis cases that give the maximum and minimum components are used for this combo. Therefore the load Combo holds two values for each output segment and joint. The Combo Type can be used for moving loads and any analysis case where the load producing the maximum or minimum force/stress is required.

• Absolute Add. The absolute of the individual analysis case results are summed and positive and negative values are automatically produced for each output segment and joint. Use this Combo Type for lateral loads.

• SRSS. The Square Root Sum of the Squares calculation is performed on the analysis cases and positive and negative value are automatically produced for each output segment and joint. Use this Combo Type for lateral loads.

4. Select the appropriate action:

• Add button

1. Select an analysis case name from the Case Name drop-down list box and type in the multiplier in the Scale Factor edit box. The Case Type display box shows the type of analysis specified for the associated Analysis Case name.

2. Click the Add button to add the analysis case and multiplier to the Case Name/Scale Factor display areas.

• Modify button

1. Select the analysis case/multiplier to be modified in the Case Name/Scale Factor display areas.

2. Type the revisions into the Case Name/Scale Factor edit boxes.

3. Click the Modify button.

• Delete button

1. Select the analysis case/multiplier to be deleted in the  Case Name/Scale Factor display areas.

2. Click the Delete button.

• Modify/Show Combo button

1. Select the load combination to be modified in the Combinations display area.

2. Click the Modify/Show Combo button to access the Define Response Combinations form.

3. Make the necessary adjustments using the options on the form

4. Click the OK button to return to the Define Response Combinations form. Then click the OK button on that form to close it.

• Delete Combo button

1. Select the load combination to be deleted in the Combinations display area.

2. Click the Delete Combo button.

• Add Default Design Combos button. Click the button to access the Add User Default Design Combinations form. Use that form to automatically define load combinations based on design type (e.g., steel frame, concrete frame, aluminum frame, cold-formed steel frame). Design load combinations, or "design combos," are the various combinations of the analysis cases that SAP2000 will use in checking the model.

Example:  Definition of combinations is demonstrated in Problem A, Problem B, Problem I and Problem U.  

See Also

Aluminum Frame Design - Select Design Combos

Cold-Formed Steel Frame Design - Select Design Combos

Concrete Frame Design - Select Design Combos

Steel Frame Design - Select Design Combos