Thanks very much for your helpful and quick reply
1. If the probe->position is only for the rigid bodies, then how could I get the displacement response for the IC chip? I think it is a different result from the directional deformation. Like what you mentioned before:"If you probe the Z displacement of a point on the IC, you have to subtract the Z displacement of the input to the faces fastened to the shaker to get the relative displacement." How did you get the Z displacement response? Why do we need to use the relative displacement instead of absolute displacement? If I do not subtract the Z displacement of the input, does it means that I will get the absolute displacement?
2.How did you get the following table from Modal Analysis?
Is there any possible solution that we could derive the mass participation within different mode shapes in Nonlinear Case? Since I was also very interested in this part.