Finite element analysis of transmission of leaky Rayleigh waves at the extremity of a fluid-loaded thick plate

Abstract

A numerical study based on finite element simulations reveals the experimentally indicated fact [N. F. Declercq et al., J. Appl. Phys. 96, 5836 (2004)] that leaky Rayleigh waves propagating along the horizontal surface of a thick fluid-loaded solid plate are transmitted around the corner of the solid plate. The mentioned experiments are based on the so-called Schoch effect, accompanied by the presence of a null strip in the reflected part of the beam, and phenomena occurring when the incident beam, generating the effect, approaches the edge of the solid plate. The referred experiments indicate that leaky Rayleigh waves are generated around the corner of the plate, but the experimental evidence is not fully conclusive whether the effect is caused merely by incident Rayleigh waves on the upper surface or by scattering effects when the incident beam interacts with the corner. The current study first confirms the reported experiments by means of the finite element method and then proofs that the assumption made in the referred paper about Rayleigh waves, being primarily stimulated by the edge of an incident bounded beam rather than the middle, is correct. Ultimately the model is applied to study leaky Rayleigh waves separately from the incident and reflected bounded beams. It is shown that the Rayleigh waves themselves are the physical origin of the transmission of Rayleigh waves rather than scattering effects caused by the incident bounded beam.