Numerical investigation of the functionally graded materials by the interaction of the plate guided waves with discontinuities and cracks

Abstract

This work intends to give a better comprehension of the guided wave interactions with damage in a functionally graded material (FGM). For this purpose, a two dimensional finite element (FE) method is used to analyse the near field surrounding the damage. Then, the expansion of the solution into sums of guided modes enables the determination of the reflection and transmission coefficients of each existent mode. The determination of the dispersion curves is ensured by the way of the so called semi-analytical finite element (SAFE) method applied to the one dimensional inlet and outlet cross-sections. Results are obtained by solving the global system of the 2D hybrid FE-SAFE method. The latter has the benefit to study an arbitrary shape-like damage in an infinite structure having the same shape by translation in the propagation direction in a fast and efficient way. The work aims to predict the propagation and interactions of plate guided waves with discontinuities in a functionally graded material composed of ceramic and metal mixture. Different symmetrical and asymmetrical notches are studied and so for cracks. Results are obtained and discussed for a FGM and compared to those obtained for an isotropic material. © 2013 Acoustical Society of America.