Identification of nonlinear finite element model through discrete-time Volterra series

Philippe Bussetta¹; Sidney Bruce Shiki¹; Samuel da Silva¹

¹ UNESP - Univ Estadual Paulista

doi:10.20906/CPS/COB-2015-0186

Resumo

In many mechanical systems, the dynamical behaviour is needed to design and to control the integrity of these structures. The numerical modelling is a very powerful tool to understand the dynamical behaviour. Nevertheless, the identification of the numerical parameters is not easy. This work deals with the identification of nonlinear finite element model using discrete-time Volterra series. The main idea of the Volterra series is to describe the discrete-time output of a nonlinear system using multidimensional convolutions between the Volterra kernels and the excitations. A metric based on the residue between the experimental and the numerical Volterra kernels is used to identify the parameters of the numerical model. First, the identification of the linear parameters is performed using a metric based only on the first order Volterra kernels. Then the nonlinear parameters are identified through a metric based on the higher-order kernels. To put in light the applicability of this technique, this work focus on the identification of the some parameters in a nonlinear finite element model of a buckled beam that can be preloaded by compression mechanism. This work shows that essentially the output signal from the numerical model after the updating and the experimental one are similar.

Palavras-chave: Volterra series; model updating; nonlinear finite element model; nonlinear identification