Nonlinear damping estimation from rotor stability data using time and frequency domain techniques

Abstract

For estimating equivalent damping characteristics from transient response data involving nonlinear damping, modifications to two stability testing methods, the moving-block technique and the sparse time domain method, are presented and verified by the use of numerical simulations. Effects of large undamped response and noise on the performance of these techniques are evaluated for quadratic and coulomb dampings. It is concluded that equivalent damping characteristics may be identified from sampled, multimode and noisy nonlinear transient response data using modified versions of the moving-block analysis and the sparse time domain method