Speaker: Praveen Gurrala, ECpE Graduate Student
Advisor: Jiming Song
Title: Full-wave Modeling of Ultrasound Scattering in Ultrasonic NDE Systems
Abstract: Advances in the ability to predict material failure under service loading has allowed the acceptance of materials with defects, provided quantitative information about the defects such as their size, location, orientation etc. is known. Increasingly, nondestructive evaluation (NDE) methods aim to provide such a quantitative description of the defects in materials. Given the uncertainties in NDE calibration and inspection procedures, good NDE models are not only helpful but also, to a certain extent, required for the development of quantitative NDE methods. In this seminar, I will present my research in developing accurate models of ultrasonic NDE systems, focusing on the phenomena of ultrasound scattering from defects. State-of-the-art models for ultrasound scattering include the Kirchhoff approximation (KA) and the boundary element method (BEM), which is more accurate and computationally demanding than KA. The predictions of these models for benchmark problems will be shown to demonstrate the need for accurate models such as the BEM. The computational cost of the BEM can be reduced by adopting higher-order discretization of the underlying boundary integral equations and using fast algorithms for computing matrix-vector products. Application of these techniques has been restricted to integral equations that are ill-conditioned at certain ultrasound frequencies. Preliminary work on extending these techniques to more robust integral equations will be presented.