Optimization for ultrasonic inspection of austenitic welds and components

The ultrasonic inspection of austenitic welds is an important problem in liquid metal cooled fast reactors. The grains in these welds may be columnar with length greater than the ultrasonic wavelength. Such a material appears to the ultrasound to be inhomogeneous and anisotropic. In order to understand the propagation and scattering of the ultrasound in such media, a numerical model has been created, based on finite difference approximations to the wave equation. The model is presented in this paper. Time dependent solutions are calculated in three spatial dimensions for a finite width beam of finite duration in a material with arbitrary inhomogeneity and anisotropy within the calculational region