Using the Damping subnode, you can add damping to the material model. Damping can be used in Time Dependent, Eigenfrequency, and Frequency Domain studies; for other study types, the settings in the Damping subnode are ignored.
In this damping model, the damping parameter ξ is expressed in terms of the mass m and the stiffness k as
That is, Rayleigh damping is proportional to a linear combination of the stiffness and mass; there is no direct physical interpretation of the mass damping parameter αdM and the stiffness damping parameter βdM.