Efficiency of Higher Order Finite Elements for the Analysis of Seismic Wave Propagation

TL;DR

This paper investigates the effectiveness of higher order finite elements, specifically 15-node elements, in accurately modeling seismic wave propagation, focusing on numerical dispersion and attenuation in linear damped media.

Contribution

The study provides a detailed analysis of numerical dispersion effects of higher order finite elements in seismic wave simulations, highlighting their advantages over lower order models.

Findings

Higher order 15-node finite elements reduce numerical dispersion.

The analysis demonstrates improved accuracy in wave velocity modeling.

Attenuation modeling benefits from the rheological interpretation of classical assumptions.

Abstract

The analysis of wave propagation problems in linear damped media must take into account both propagation features and attenuation process. To perform accurate numerical investigations by the finite differences or finite element method, one must consider a specific problem known as the numerical dispersion of waves. Numerical dispersion may increase the numerical error during the propagation process as the wave velocity (phase and group) depends on the features of the numerical model. In this paper, the numerical modelling of wave propagation by the finite element method is thus analyzed and dis-cussed for linear constitutive laws. Numerical dispersion is analyzed herein through 1D computations investigating the accuracy of higher order 15-node finite elements towards numerical dispersion. Concerning the numerical analy-sis of wave attenuation, a rheological interpretation of the classical Rayleigh assumption has for instance been previously proposed in this journal.