Erik Kostson
Ansys Employee


See that discussion Peteroznewman explains what Ansys does when you give a frequency of interest (say the freq. of your dominant mode of interest that will be excited – frequency_given) and a damping ratio (damp_ratio_given).

As he says, it calculates 
beta = (2*damp_ratio_given)/(2*PI*frequency_given).

You can check that in Ansys yourself, by giving freq. = 20 Hz, damping ratio = 0.01, then Ansys will give a beta as =


All the best, and perhaps some other forum members can give some more feedback, but the post and this should explain (also see some more material on the internet about Rayleigh damping.