What type of element formulation have you used? What BCs are you applying and to which nodes?

It appears from your results plots that you may be using a single layer of 3D continuum solid elements. If this is the case, it is likely that the only DOFs in the problem are translational displacements. In this case, you won't see any difference in results by specifying zero (fixed) rotational DOFs, because none exist. By the way, if you are using a solid element, you should probably use several elements through the thickness to capture the gradients in normal strain more accurately.

raja,

almost you are right but the rotational axis is wrong ,you have give x-axis has rotational axis according bto your modal.further you have to increase the frequency

I tried with x-axis rotation, it shows the same result.

I tried with x-axis rotation it shows the same result.

Hello Mr.Raja , please go through the tutorials of ansys .

It will help u to solve the problem.

Have you tried to increase the BC a bit and check its influence on final result. You need to perform troubleshooting.

You need to perform a linear perturbation modal analysis. This is a two step procedure, which you may not have correctly implemented in Workbench.

I recommend using ANSYS APDL to understand the concept of this analysis. Attached is an example with a rotating mass attached to the end of a cantilevered beam. The code demonstrates the fundamental principles of this type of analysis.

Thanks for the information sir Sven Rechenberger. I will go through this and i will update you.

For the time being, use a simple beam element representation for testing. Once you are happy with the results, you can simply change the element topology to any level of complexity needed to analyse your problem.