Asymptotic modelling of the Rayleigh-Bloch waves travelling along a periodically-perturbed elastic surface, by Aleksey Pichugin (Brunel University London)

DENORMS Action’s Workshop “Modelling of high performance acoustic structures Porous media, metamaterials and sonic crystals”, Rome, 24-25th January 2017

Website of DENORMS Action

Programme of the Workshop

Session on New trends in vibroacoustics (i.e. elastic metamaterials and metasurfaces)

Speaker: Aleksey Pichugin (Brunel University London)

Abstract:

It is well-known that a free surface of an elastic half-space can support inhomogeneous waves that propagate along the surface and exponentially decay away from it. These Rayleigh waves propagate without dispersion and can be shown to exist in a wide range of practically-relevant settings (including material anisotropy and surface curvature). In this paper we will investigate how a series of small-scale periodic perturbations to the surface can modify the behaviour of the Rayleigh waves, by introducing dispersion and forming phononic band gaps. A simple model problem will be used to illustrate the relevant physical phenomena and the technique of high-frequency asymptotic homogenization will be used to construct a simple analytical model for the resulting Rayleigh-Bloch waves.