| This dissertation models the sound fields produced by ultrasonic transducers for immersion inspections where the sound fields pass through general curved interfaces into a general anisotropic material.;The foundations for these models are discussed, including slowness surfaces for anisotropic materials and the reflection/transmission of plane waves at a planar fluid/anisotropic solid interface.;Three beam models are developed. Two of these models---the boundary diffraction wave model and the multi-Gaussian model---rely on the paraxial approximation, resulting in models that are computationally very efficient. As a consequence, those models can be used to conduct parametric studies in a highly effective manner. The third model is a more 'exact' model, based on the numerical evaluation of an angular spectrum of plane waves integral with Hopkins' method. This 'exact' model, although computationally less efficient than the paraxial models, can handle the special cases where the paraxial approximation can fail. The beam models are compared to each other for a variety of test cases and limitations of the paraxial models are discussed. |
