bhagwantP
Ansys Employee

Hello aitor,

During prestressed modal analysis, it does consider updated stiffness and mass matrix from static structural analysis but during mode shapes deformation it shows on undeformed body only. Not on deformed body due to prior run static analysis but at background it does all math to consider prestress effect. Mesh is shown with respect to the undeformed position only. 

There are some ways which you can employ deformed geometry but for visulization purpose:

">

Add on discussions:

Pre-Stressed Modal Analysis, Nonlinear Static | Ansys Workbench (simutechgroup.com)

https://forum.ansys.com/forums/topic/modal-analysis-on-static-structural-results-deformed-prestressed/

Hope it helps.

Thanks