Nonlinear parameter estimation in damping with volterra series through harmonic probing

Abstract

In this work nonlinear system identification procedure, based on Volterra series, is presented to distinguish a damping nonlinearity from stiffness nonlinearity, using measured first and third harmonic amplitude characteristics. First and higher order volterra kernel synthesis formulations and frequency response functions (FRFs) have been developed in damping and stiffness nonlinearity. The characteristics of first and higher order harmonic amplitudes at various excitation level is studied for the both the nonlinearity. This paper shows comparison study between the Volterra series, Runge-Kutta fourth order in analysis of damping and stiffness nonlinearity in the mechanical systems. Nonlinearity can lead to various system behaviour, like jump phenomenon, stable and unstable region, super harmonic resonances. Using first and higher order harmonic amplitudes, formulated from Volterra series response representation, nonlinear parameters are estimated through the recursive iteration method.