Thanks, this clarifies my doubt. So, if I have a damper in my system (e.g. a viscous damper in a specific location, with a known "c" in N*s/m), what is the best way to simulate its damping behaviour in a MSUP analysis? I'm using the bushing element, and I'm assigning a constant damping with MP,dmpr, and I'm computing the value as c/(2*sqrt(k*m)), thus setting the damping ratio with respect to the first mode even if the component is involved in many other modes of the assembly. Is it reasonable?

Additionally, is there an easy way to plot the distance between two points in frequency domain? The only way I can think about is to export to matlab ux, uy and uz of both points and do some computation outside ansys,  but I would really appreciate if I could define this result (in frequency domain) inside the ansys workbench simulation.