Nonreflecting boundary conditions for elastodynamic scattering

An exact nonreflecting boundary condition was derived previously for time-d ependent elastic waves in three space dimensions [SIAM J. Appl. Math. 60, 8 03 (2000)]. It is local in time, nonlocal on the artificial boundary, and i nvolves only first derivatives of the displacement. Here it is shown how to combine that boundary condition with finite difference and finite element methods. Stability issues are discussed. Numerical examples with a finite d ifference method demonstrate the high improvement in accuracy over standard methods. (C) 2000 Academic Press.