Coupling of Shear Acoustic Waves by Gratings: Analytical and Experimental Analysis of Spatial Periodicity Effects

Abstract

A model, presented in a previous paper [J. App. Phys. 108 (2010) 074910], describing the modes coupling due to scattering on small one-dimensional irregularities (parallel ridges) of the surface of isotropic solid plates, when shear horizontal waves polarized along the ridges propagate perpendicularly to them, appears to be a convenient tool to tackle the effects of the shape profile of the ridges (including the depth and the slope). Being concerned by the use of this analytical approach not utilised until now, several results, yet typical of applications, are presented below and compared with some experimental and numerical results, even analytical results (from an alternative analytical model for particular cases). These comparisons permit to highlight the effects of spatial periodicities of the ridges and show that the method could provide information on geometrical parameters characterising the profile of the roughness, which could be of interest when other methods like optical methods cannot be used.