Thank you for your answer! Sorry for my late reply I forgot that I asked a question here.

I want to analyse a beam embedded in a viscoelastic material (embedded meaning completely surrounded in radial direction). My goal is to find out how the eigenfrequencies change due to the surrounding viscoelastic material.

When I asked my question I thought it would be a good idea to use nonlinear springs. By now, I switched to using COMBIN14 elements for the beam model. I also have a beam model made of volume elements where I enter the viscoelastic material properties as experimental data.

I know that modal analysis in Ansys are linear but I can't help to think that there must be a way to conduct a nonlinear modal analysis. I would once more really appreciate it if someone could point me into the right direction with this problem.