Evolution of a semidiscrete system modeling the scattering of acoustic waves by a piezoelectric solid

TL;DR

This paper models the scattering of acoustic waves by a piezoelectric solid, analyzing well-posedness and proposing a semidiscrete finite element and boundary element approach, with simulations demonstrating properties of the full model.

Contribution

It introduces a semidiscrete formulation combining finite element and boundary element methods for a piezoelectric scattering problem, improving previous Laplace domain estimates.

Findings

Well-posedness established via reformulation as a first order system

Semidiscrete formulation demonstrates convergence properties

Simulations illustrate characteristics of the full two-dimensional model

Abstract

We consider a model problem of the scattering of linear acoustic waves in free homogeneous space by an elastic solid. The stress tensor in the solid combines the effect of a linear dependence of strains with the influence of an existing electric field. The system is closed using Gauss's law for the associated electric displacement. Well-posedness of the system is studied by its reformulation as a first order in space and time differential system with help of an elliptic lifting operator. We then proceed to studying a semidiscrete formulation, corresponding to an abstract Finite Element discretization in the electric and elastic fields, combined with an abstract Boundary Element approximation of a retarded potential representation of the acoustic field. The results obtained with this approach improve estimates obtained with Laplace domain techniques. While numerical experiments illustrating convergence of a fully discrete version of this problem had already been published, we demonstrate some properties of the full model with some simulations for the two dimensional case.