Although equivalent viscous damping is independent of frequency, it is only possible to use it in a frequency response analysis. Equivalent viscous damping also uses a loss factor as the damping parameter, and can be implemented using the Rayleigh damping feature, by setting the stiffness damping parameter βdK, to the loss factor, η, divided by the excitation frequency:

The mass damping factor, αdM, should be set to zero.