View Parts Ranked by Rigid Body Motion

Show a list of parts ranked by movement amplitude for a given mode shape.

This process will help diagnose vibration and connection problems in complex assemblies. Problems can arise due to the following:
  • Part stiffness is too low – likely cause is an incorrectly specified material property. Check to make sure the right material is applied and check the material property to make sure it has the proper modulus of elasticity.
  • Part mass is too high – likely caused by either an incorrectly specified material property or an incorrect rigid part mass density. Check to make sure the right material is applied and check the material property to make sure it has the proper density. If the part is rigid, check the density or mass specification.
  • Part is insufficiently constrained – the part connection may be insufficient and a hinge (mechanism movement) is occurring. This is commonly observed when a part is flapping unnaturally during the modal animation. Exit the mode shape results display and check part connections.

  1. In the Project Tree, open the Analysis Workbench.
  2. On the workbench toolbar, click the (Check rigid motions) icon.
    If the structure is not sufficiently constrained, a Warning dialog will appear.
  3. In the dialog, click Yes to see the rigid body motions found.
    A Motions dialog will appear and show all rigid body motions found in the model. You can select a motion from the list, then click the (Animation) button to see how the part is moving.