A FREQUENCY-DOMAIN PARAMETRIC IDENTIFICATION METHOD FOR STUDYING THE NONLINEAR PERFORMANCE OF SQUEEZE-FILM DAMPERS

An efficiency frequency domain method for estimating the unknown param eters in linear-in-the-parameter, non-linear systems is developed. By applying window functions directly to the various terms in the equatio ns of motion, rather than to the measured data, differentiation of the data is completely avoided. Simulation tests applied to a non-linear model of a squeeze-film damper, executing both radial motion and circu lar centred orbits, show that the proposed method can provide satisfac tory estimates of various unknown parameters. Some experimental result s for both radial motions and circular centred orbits are also given. (C) 1996 Academic Press Limited