Defining Contact Status for a Prestressed Modal Analysis

Question: What is the difference between choosing True Status, Force Sticking or Force Bonded contact status for prestressed modal analysis? 

Answer: The Linear Perturbation method allows you to define what contact status from your static analysis you want to use. For example, if you define a nonlinear type of contact in your static analysis, you can select how you want that status to translate into the modal analysis. In the prestress settings for the modal you can choose to use the "True Status" from the static - which would take in account sliding, sticking, etc. You could choose "Force Sticking" which would force any contact regions that were sliding to become a sticking status for the modal. Lastly, you can specify "Force Bonded" and by doing this, it will bond all the contact regions that were sliding or sticking.

Here is a good example from the Ansys help documentation that shows how you can select a certain contact status for the modal analysis and how it will affect the frequencies and mode shapes - Cyclic Symmetry Analysis of Rotor and Brake Assembly