Computer simulation of acoustic waves propagation in elastically anisotropic materials

A computer simulation technique for 3-dimensional ultrasonic waves was developed for visualization and investigation of ultrasonic propagation in isotropic and anisotropic solids. The technique is based on a finite-difference method (FDM) and a mass-particle model method, but uses a new nodal calculation method following fundamental consideration of the elastic wave equations. The new method simplifies calculations on boundary nodes, so that it requires no pseudo-nodes as used in the FDM, and is applicable to not only anisotropic but also combined materials including defects. The technique still has limitations on the applicable type of stiffness matrix for anisotropic materials. Under the limitations of the stiffness matrix and computer performance, we present conventional applications for the 2-dimensional condition including 3-dimensional motion. Some simple applications are shown for ultrasonic propagation in anisotropic (hexagonal and cubic) materials, including cracks or voids, and composite materials.