Load Sets for Analysis
The Loads area appears on the following dialog boxes:
• PreStress Modal Analysis Definition
The Loads area has the following items:
• Load Set / Component—Displays all the load sets defined in the model. It also displays the name of the component for which you have defined the load set. The component name can be that of a part, subassembly, or assembly. If you move the pointer over the component name, the assembly path and the component ID are displayed. The assembly path is a hierarchical list of all assemblies and sub assemblies of which the component is a part.

On the Static Analysis Definition dialog, if you select the Nonlinear / use load histories check box, the MEC/T history loads created for the model appear in the Load Set / Component list. The function field is set to Mec/T Hist. However, the function button and the function field are inactive. You can select only one load set that contains a MEC/T history load at a time. 
• Time Dependence—Defines individual histories for each load set. Available only if the Nonlinear / use load histories check box is selected. The time dependence function multiplies each load in a load set by the value of the function at a given time.
Use the default
ramp function for time dependence or click
to open the
Functions dialog box. Click
New to create a new
table function using the
Function Definition dialog box. The independent variable of the function is time and the dependent variable of the function is a quantity without units.
 You cannot create symbolic functions for time dependence. 
 You need to note here that for a steady state thermal analysis or a static analysis the time dependence function is used only to define the order in which loading is carried out. It is assumed that the loading is carried out so slowly that true transient or dynamic effects are neglected. 
When you define output steps for an analysis you specify the steps at which to calculate results. Results at specified steps are calculated for the corresponding value of load based on the time dependence function. The maximum step is the maximum value of time in a time dependence function.
• Sum Load Sets—Merges the loads of all the selected load sets into a new single load set. Select one or more load set to include in the analysis. Select the
Sum Load Sets check box to merge these selected load sets into a single new load set. The new load set is named
SummedLoadSetX, where X is the lowest natural number used to define a unique name for the new set.
If you do not select the Sum Load Sets check box, the results are calculated separately for each load set that you include in the analysis.
 This check box is not available if you select the Nonlinear / use load histories check box. In this case if you have included more than one load set, they are summed automatically into a single load set. 
For more information about including load sets in structural analyses, see
Constraint and Load Sets in Structural Analyses.