DEVELOPMENT OF 3-DIMENSIONAL ULTRASONIC SIMULATION AND ITS APPLICATION

A computer simulation technique for 3-dimensional ultrasonic waves was developed for visualization and investigation of ultrasonic propagati on in isotropic and anisotropic solids with defects. The technique is similar to a finite-difference method (FDM) and a mass-particle model method, but uses a new nodal calculation method based on fundamental c onsideration of an elastic wave equation. The new method simplifies ca lculations on boundary nodes, so that it requires no pseudonodes as in the FDM, and is applicable to not only anisotropic but also complex m aterials including defects. A program has been developed for 3-dimensi onal calculation, but it requires the huge memory and high speed of su percomputers. Due to the limitation in computer performance, we presen t here conventional applications under the 2-dimensional condition inc luding 3-dimensional motion. Some simple applications are shown for ul trasonic propagation in anisotropic (hexagonal) materials and layered materials, and wave scattering at a crack.