Simulation of ultrasonic fields propagating through nonparallel boundaries

Abstract

The main objective of this paper is to present an efficient method suitable for simulation of ultrasonic fields radiated through the layers with nonparallel boundaries. The proposed method enables fast calculation of an ultrasonic disk-shaped transducer field transmitted through parallel and nonparallel boundaries between layers. The proposed simulation method is based on transformation of a multilayered medium into a virtual one without internal boundaries, equivalent to the actual medium from the point of view of the relative times of arrival of direct and edge waves. Such an approach enables one to exploit the modified axially symmetric model and to simplify the computations essentially. The example of simulated fields is presented for the case of plastic materials.

Simulation of ultrasonic fields radiated by a circular source through a layer with nonparallel boundaries

“…For this purpose, the known model for calculation of the ultrasonic field of a single circular transducer in a homogeneous medium 17 and the extended model for the case of a multi-layered medium with parallel or nonparallel boundaries 18,19 were modified to take into account the multiple reflections inside the layer. The proposed simulation method is based on transformation of a multi-layered medium into a virtual one without internal boundaries and equivalent to the actual medium from the point of view of the times of flight of direct plane and edge waves.…”