An adaptive perfectly matched layer finite element method for acoustic-elastic interaction in periodic structures

TL;DR

This paper develops an adaptive finite element method with a perfectly matched layer for simulating acoustic-elastic interactions in periodic structures, ensuring accuracy and efficiency through error estimation and adaptive refinement.

Contribution

It introduces a novel adaptive PML finite element approach with residual error estimates for acoustic-elastic problems in periodic media, improving computational accuracy.

Findings

The method achieves exponential convergence.

Numerical examples confirm the effectiveness of the adaptive algorithm.

The approach accurately handles non-smooth elastic surfaces.

Abstract

This paper considers the scattering of a time-harmonic acoustic plane wave by an elastic body with an unbounded periodic surface. The original problem can be confined to the analysis of the fields in one periodic cell. With the help of the perfectly matched layer (PML) technique, we can truncate the unbounded physical domain into a bounded computational domain. By respectively constructing the equivalent transparent boundary conditions of acoustic and elastic waves simultaneously, the well-posedness and exponential convergence of the solution to the associated truncated PML problem are established. The finite element method is applied to solve the PML problem of acoustic-elastic interaction. To address the singularity caused by the non-smooth surface of the elastic body, we establish a residual-type a posteriori error estimate and develop an adaptive PML finite element algorithm. Several numerical examples are presented to demonstrate the effectiveness of the proposed adaptive algorithm.