A Simple Numerical Absorbing Layer Method in Elastodynamics

TL;DR

This paper introduces a simple, efficient absorbing layer method using Rayleigh/Caughey damping within the Finite Element Method to reduce spurious reflections in elastic wave simulations in unbounded media.

Contribution

It presents a novel, straightforward absorbing layer technique that effectively handles various wave types and incidences in elastodynamics simulations.

Findings

Effective reduction of spurious reflections in 1D and 2D simulations.

Works well for different wave types and incidence angles.

Simple implementation within existing FEM frameworks.

Abstract

The numerical analysis of elastic wave propagation in unbounded media may be difficult to handle due to spurious waves reflected at the model artificial boundaries. Several sophisticated techniques such as nonreflecting boundary conditions, infinite elements or absorbing layers (e.g. Perfectly Matched Layers) lead to an important reduction of such spurious reflections. In this Note, a simple and efficient absorbing layer method is proposed in the framework of the Finite Element Method. This method considers Rayleigh/Caughey damping in the absorbing layer and its principle is presented first. The efficiency of the method is then shown through 1D Finite Element simulations considering homogeneous and heterogeneous damping in the absorbing layer. 2D models are considered afterwards to assess the efficiency of the absorbing layer method for various wave types (surface waves, body waves) and incidences (normal to grazing). The method is shown to be efficient for different types of elastic waves and may thus be used for various elastodynamic problems in unbounded domains.