THE ELASTODYNAMIC FINITE INTEGRATION TECHNIQUE FOR WAVES IN CYLINDRICAL GEOMETRIES

This paper deals with the elastodynamic finite integration technique f or axisymmetric wave propagation in a homogeneous and heterogeneous cy lindrical medium (CEFIT). This special variant of a finite difference time domain (FDTD) scheme offers a suitable method to calculate real t hree-dimensional problems in a two-dimensional staggered grid. In orde r to test the accuracy of the numerical CEFIT code, problems for which analytical solutions are available are presented. These solutions inv olve wave propagation in an elastic plate, the scattering of a plane l ongitudinal wave by a spherical obstacle, and ultrasound generation by a thermoelastic laser source. For the latter problem experimental res ults are included. The CEFIT code also allows the treatment of more co mplicated problems. Further possible applications are the investigatio n of elastic waves generated in an acoustic microscope, the simulation of impact-echo measurements in multi-layer systems, axisymmetric wave propagation in arbitrary bodies of revolution, the calculation of ela stic wave fields of longitudinal wave transducers with a circular aper ture, and the investigation of multi-layer models for particulates. (C ) 1998 Acoustical Society of America. [S0001-4966(98)01911-0].