Initial parameters estimation for Euler-Bernoulli beam fitting of measured frequency response functions

Abstract

In receptance coupling studies, Euler-Bernoulli beam fitting is a powerful method to derive the rotational receptances from a single frequency response function or displacement-to-force receptance measurement. To automatically complete this method, optimization algorithms are used. For optimization process, initial beam parameters including diameter, length and solid damping factor for each mode in the measured displacement-to-force receptance are required to start iterative search. As such, exploring those initial parameters is sort of trial-and-error work and takes quite some time. To speed up and automatize this work, in the current paper, a new practical, general and easy to implement initial parameters estimation procedure, based on the peak-picking method, is proposed. For verification, a nonlinear least squares fitting-based algorithm is applied on measured spindle-holder subassembly displacement-to-force receptances. The results have shown that the estimated initial beam parameters lead to a quick converge in the optimization process and a successful Euler-Bernoulli beam fitting. • A new practical procedure for initial beam parameters estimation is proposed for EulerBernoulli beam fitting. • The proposed procedure remarkably prevents the time-consuming work to determine initial beam parameters. • Its implementations are performed on measured spindle-holder subassembly displacement-to-force receptances. • The proposed procedure certainly improves success probability of optimization algorithms.