A Receiver Model for Ultrasonic Ray Tracing in an Inhomogeneous Anisotropic Weld

In this paper, a receiver model for ultrasonic ray tracing simulation is described. This is a complementarypart of an existing simulation model and is the next step towards a numerical solutionto the inverse problem and thus a NDT methodology for characterization of the dendrite orientationin a weld. The establishment of the receiver model is based on the electromechanical reciprocityprinciple. A concise retrospect of the weld model and the 2D model is made. The reciprocityprinciple is applied in an original way to handle the model problem including the back wall.Experimental qualitative validations for both P and SV waves on a specific weld are also made forC-scans included in this paper. Two different cases are studied. The first is a direct incidence of anultrasonic ray towards the weld, and the second is a reflection from the back surface in the basematerial followed by an incidence to the weld. Even though mode-converted rays are excluded inthe simulations, both the P and SV probe-models show the same behavior as the experimental results.The qualitative validation though reveals that it even if a thorough time-gating of receivedinformation would enable exclusion of mode-conversion in the model, inaccuracy of experimentalresults is affecting the evaluation of the weld model