A transmitting boundary for the numerical simulation of elastic wave propagation

Abstract

A numerical method for transmitting waves out of an artificial boundary is presented. It is applicable to linear two- or three-dimensional wave problems with a time-stepping algorithm and a convex artificial boundry. This numerical scheme, expressable in the form of an extrapolation formula, can be implemented easily in finite elements or finite differences. The values at the artificial boundary nodes are calculated with only interior nodal values from time steps past. Limitations of this method are approximately the same as those of the finite element method. The accuracy is controlled by the number of terms in the extrapolation series and can be further improved by decreasing the size of the time step.