The Computational Accuracy of 3D Elastic or Viscoelastic Wave Propagation by FEM

Abstract

A three-dimensional FEM (finite element method) for solving elastic or viscoelastic wave propagation problems are tested. Viscoelastic wave equations are introduced by three relaxation mechanisms. Second-order polynomial interpolation function and perfectly matched layer (PML) absorbing boundary condition are composed to this FEM framework. Also, it performs effective CPU time reduction by parallel computing. The accuracy of the FEM is evaluated by three tests. FEM is compared to the analytical solution for Lamb’s problem and the semi-analytical solutions for layered elastic or viscoelastic media. Especially, FEM and the analytical solution for Lamb’s problem showed almost perfect convergence. Therefore, we conclude that FEM produces very exact waveform. Moreover, this conclusion can support the accuracy of FEM for viscoelastic wave equations.