Local damage identification method using finite element model updating based on a new wavelet damage function

Abstract

As the number of unknown parameters in a finite element model updating problem increases, the challenges in finding reliable and meaningful updating result surges. Although traditional damage functions have illustrated an excellent ability in reducing unknown parameters, they are imprecise for identifying local damages. To solve this problem, a new type of damage function termed the wavelet damage function, which specializes in local damage identification, is proposed in this article. It utilizes the properties of the Haar wavelet and wavelet multi-resolution analysis. During the wavelet damage function–based finite element model updating procedure, unknown parameters in finite element models are not directly adjusted. Instead, wavelet coefficients of the parameters are estimated stepwise and then the final updating results are reconstructed through the inverse discrete wavelet transform. Numerical simulations and experimental verifications are conducted, and the corresponding results show that wavelet damage function can offer better accuracy as well as higher computational efficiency in the identification of local damages than the traditional damage functions.