This window is displayed when you create a new analysis or open an existing analysis. It is displayed as a floating window separate from the main application window. Closing this window will not close the analysis itself and will not lose any information about the analysis. To redisplay this window (when an analysis is open), select Analysis Inputs from the View menu, or press F4.
This tab contains inputs for the load combinations to analyze. A load combination is a set of loadings with corresponding load factors. The grid displays the loadings and factors for one combination at a time. You may define several load combinations, but you may only analyze one combination at a time. See also General Tab, Members Tab, Supports Tab, Loadings Tab, and Notes Tab.
| Combination | The name associated with the load combination. This name may be changed to any name not already used. To view the loadings and load factors for a different combination, select its name from the list. There is always one more entry in the list than there are combinations currently defined. To add a combination, select the last entry in the list and optionally rename it. You may delete a combination by deleting its name and pressing Enter. |
| Use Inflection Point Bracing | Check this box if you want the analysis to treat inflection points as brace points for the current load combination. |
| Specification | Choose the design specification to be used with the current load combination. If the load combination uses unfactored loads, select an ASD specification. If the load combination uses factored loads, select an LRFD or LSD specification. If a load combination should not be used in strength checks (member checks or web-crippling checks), select "Deflection Only" as the Specification. |
| For All Strength Combinations | Check this box to force all load combinations to use the same Specification selection. |
| Loading | The name of the loading to include in the current combination. This drop-down list contains all of the loadings currently defined in the analysis, plus member self weight. The self weight loading is a distributed load in the negative Y direction, based on each members’ cross section area and a density of 0.2833 lb/in³. To add a loading to the combination, enter its name in the blank row after the last loading in the combination. To add a loading that does not yet exist, you must first create it on the loadings tab. |
| Load Factor | The multiplier to apply to all the loads in the loading. This may be positive or negative. |