Analysis of stress effect on Lamb wave propagation in isotropic plates

Abstract

This paper presents an analysis of the stress effect on Lamb wave propagation in isotropic plates based on the theory of nonlinear elasticity. In this study the plates are assumed to be initially isotropic hyperelastic and subjected to homogeneous stress. The theory of small deformations superimposed on large deformations is used to derive the acoustoelastic dispersion equations for both symmetric and anti-symmetric modes of Lamb waves. Different magnitudes of the inhomogeneous stress are considered in this study. The results of the theoretical predications show that the acoustoelastic effect of isotropy plates subjected to a realistic level of applied stresses is quite significant, especially for higher order Lamb wave modes near the cut-off frequencies.