Numerical calculation of ultrasonic propagation with anisotropy

A computer simulation technique for three-dimensional ultrasonic propagation was utilized for the visualization and investigation of ultrasonic propagation in various materials such as anisotropic solids and combined materials. The calculation technique used here is based on a finite-difference method, but uses an improved nodal calculation method following fundamental consideration of the elastic wave equations. The improvement enabled unified treatment of calculation nodes at the inside and the boundary of the solid, and offered simplicity for calculation at the boundary and applicability for combined and anisotropic materials with limitation on the applicable type of anisotropic stiffness matrix. Here, we present the applications of the calculation technique for the two-dimensional and three-dimensional ultrasonic propagation relating to nondestructive material evaluation using ultrasound, and show the usefulness and applicability for the complex ultrasonic phenomena observed in ultrasonic measurements. (C) 2000 Elsevier Science Ltd. All rights reserved.