Modeling Ultrasonic NDE Benchmark Problems Using Full-Wave Scattering Models

Many ultrasonic non-destructive evaluation measurement models use a composite technique in which processes such as transduction, beam propagation, scattering etc. are described separately using sub-models. The output response in these composite models is then obtained by combining the outputs of sub-models using analytical techniques. The Kirchhoff approximation (KA) has typically been a preferred approach for modeling the scattering of ultrasonic waves from defects because it is less resource-intensive than full-wave scattering (FWS) models. In this paper, we study the validity (accuracy) of the KA in modeling various benchmark measurements. We describe a composite model and apply it to simulate benchmark tests. We obtain two sets of results separately with the KA and the boundary element method (BEM), without changing any of the other sub-models used in the composite model. We compare model predictions with measurement data to study the validity of KA under different test scenarios as well as to identify the use-cases for FWS models such as the BEM.