Modal and Prestress Modal Analyses

Modal and prestress modal analyses both examine the modal behavior of your model. You can use modal analysis to calculate the natural frequencies and mode shapes of your model. You can use prestress modal analyses to apply results from a static analysis and then calculate the natural frequencies and mode shapes of your model.

For a description of and requirements for each analysis type, see Modal Analysis Overview and Prestress Modal Analysis Overview.

These items appear on the Modal Analysis Definition and Pre-Stress Modal Analysis Definition dialog boxes:

• Constrained—Select this option if you want to include a constraint. Then select a constraint set from the Constraints list.

• Unconstrained—Select this option if you do not want to include a constraint.

• With rigid mode search—Use this option to include a search for rigid body modes.

The following tabs appear on the Modal Analysis Definition and Pre-Stress Modal Analysis Definition dialog boxes:

• Modes

• Previous Analysis (appears only on the Prestress Modal Analysis Definition dialog box)

• Temperature Distribution (available on the Modal Analysis Definition dialog box only for models with temperature-dependent material properties)

• Output