Constraint and Load Sets in Structural Analyses

Your model's loading condition determines the type of analysis you should use. Use the following guidelines, when you are defining structural analyses:

• For a static, prestress static, static with large deformation, and static with contact interfaces analysis, you do not need a load set if you use a constraint set with an enforced displacement. Otherwise, you must have at least one load set.

• For a linear static analysis, you need not specify any constraint if you select the Inertia Relief check box on the Static Analysis Definition dialog box. This selection allows Creo Simulate to analyze the model as if it were floating freely in space (without any constraints) but with the loads applied. However, if any of the load sets contain body loads, you cannot run the static analysis with the Inertia Relief check box selected.

• For a modal or prestress modal analysis, you do not need a constraint set if you select Unconstrained when you define the analysis. Do not select a constraint set that contains an enforced displacement constraint.

• For any analysis type other than dynamic shock, point-to-ground springs help to constrain your model. You do not have to select a constraint set if your model is sufficiently constrained by such springs.

• You can calculate results separately for each load set you include, or sum the sets as if they are acting simultaneously.

• You can combine more than one constraint set into a new single set, or calculate results for any one constraint set from the Constraints list.

• If you delete a constraint set or load set after you include it in an analysis, Creo Simulate automatically deletes that set from the analysis.

• For a linear or a nonlinear static analysis you can define individual load histories for each load set using the Time Dependence function. You can also define individual time dependence functions for each constraint set.

Even if you create a new set with the same name as the set you deleted, you must edit the analysis and select the set again. Otherwise, you may invalidate the analysis, and any design studies in which you included the analysis.