Modelling of sound fields through austenitic welds

The propagation paths of ultrasonic waves through austenitic weld material can not be predicted due to the anisotropic and inhomogeneous structure of the weld. To support an NDT-inspector Ogilvy’s ray tracing algorithm has been implemented to follow virtually in three dimensions longitudinal, horizontal and vertical polarized shear wave propagation from the basic material through the cladding. The algorithm has been implemented in a software package “3D-CAD-Ray” which allows to model the experiment in a 3D-CAD drawing and to visualize the rays including reflections from lack of side wall fusions or inner surface connected cracks. The defects can be placed, sized or oriented arbitrarily which allows to perform a parametric study. Results of the algorithm are presented and checked against the experiment. The measured elastic constants and the orientation of the grains taken from micrographs have been entered properly into the CAD-model. The spreading effect for the sound field perpendicular to the orientati...