Abnormal dispersion of fundamental Lamb modes in FG plates: II—symmetric versus asymmetric variation

Abstract

A closed-form dispersion equation for Lamb waves propagating in functionally graded (FG) plates with arbitrary varying anisotropic physical properties in transverse direction is constructed by applying Cauchy sextic formalism. Comparative analyses of the dispersion curves related to the fundamental modes of homogeneous and FG plates reveal their substantial and visually detected differences even at sufficiently small transverse inhomogeneity. The observed discrepancy in dispersion curves may serve for developing acoustic nondestructive methods for determination of possible transverse inhomogeneity.