NUMERICAL MODELING OF ELASTIC-WAVE PROPAGATION AND SCATTERING WITH EFIT - ELASTODYNAMIC FINITE INTEGRATION TECHNIQUE

The basic equations of EFIT, the Elastodynamic Finite Integration Technique, are formulated for anisotropic inhomogeneous media in 3D. For isotropic inhomogeneous media we discuss the discrete equations on a staggered grid resulting in a unique way to discretize material parameters, and evaluate stability conditions and consistency for isotropic homogeneous unbounded media. For the sake of simplified visualization, numerical results are presented for various two-dimensional problems as they originate from nondestructive testing applications. In particular, EFIT wavefronts are related to group velocity curves for anisotropic media with transverse isotropy and cubic symmetry, the latter one being derived by a coordinate-free approach in the appendix.