Problems encountered from the use (or misuse) of Rayleigh damping

TLDR: In this paper, the damping forces generated by such a matrix can become unrealistically large compared to the restoring forces, resulting in an analysis being unconservative, and a remedy to these problems is proposed in which bounds are imposed on the dampings forces.

Abstract: Rayleigh damping is commonly used to provide a source of energy dissipation in analyses of structures responding to dynamic loads such as earthquake ground motions In a finite element model, the Rayleigh damping matrix consists of a mass-proportional part and a stiffness-proportional part; the latter typically uses the initial linear stiffness matrix of the structure Under certain conditions, for example, a non-linear analysis with softening non-linearity, the damping forces generated by such a matrix can become unrealistically large compared to the restoring forces, resulting in an analysis being unconservative Potential problems are demonstrated in this paper through a series of examples A remedy to these problems is proposed in which bounds are imposed on the damping forces Copyright © 2005 John Wiley & Sons, Ltd