Study on leaky Lamb waves in functionally graded composites loaded by asymmetric fluids

Abstract

The present work aims at contributing to the investigation of a numerical method to describe the leaky Lamb waves, which propagate along the functionally graded composite plates when undergoing asymmetric fluids. The motions are considered under the two-dimensional plane strain assumption. In some respects, the proposed numerical scheme is an extension of the spectral collection method calculating the Lamb waves in a vacuum plate (stress-free on the surfaces). However, the proposed scheme implements differently because the displacement field here is influenced by both vertical heterogeneous and loaded fluids. The solution procedure relies on a linearization algorithm using a high dimensional state space, which permits the transformation of the nonlinear eigenvalue problem to the polynomial eigenvalue problem. Two comparisons are given to validate the effectiveness and support the method. Finally, results on specific examples (functionally graded composite plate immersed in the same and different fluids) are discussed to study leaky Lamb waves' propagating properties.