Stress waves in functionally gradient materials and its use for material characterization

Abstract

A method is presented to investigate elastic waves in functionally gradient material (FGM) plates excited by plane pressure wavelets. The FGM plate was first divided into linearly inhomogeneous elements (LIEs). A general solution for the equation of motion governing the LIE was derived. The general solution was then used together with the boundary and continuity conditions to obtain the displacement and stress in the frequency domain for an arbitrary FGM plate. The response of the plate to a pressure wavelet was obtained using Fourier transform techniques. Results obtained by the present method are compared with an existing method using homogeneous layer elements. Relationships between the surface displacement response and the material mechanical properties of FGM plates were also obtained. These relationships may be used for the material characterization of FGM plates.