Ray trace calculations of ultrasonic fields

Abstract

A computer code has been written to calculate realistic ultrasonic fields in solids. The program calculates the field due to a transducer coupled to the solid through either a fluid medium such as water or a solid medium such as a plastic shoe with a thin layer of fluid couplant. In this technique the transducer face is divided up into many small areas, each of which is assumed to be a source of spherical waves. A ray is traced from each source point, through the coupling medium and into the solid to the requested field point. The vector sum of the fields of each of the rays is then calculated to find the total incident field at that point for a particular frequency. The calculations have been compared to the fields predicted by the models of Thompson and Gray [R. B. Thompson and T. A. Gray, “Analytic Diffraction Corrections to Ultrasonic Scattering Measurements,” in Review of Progress in QNDE 2, edited by D. O. Thompson and D. E. Chimenti (Plenum, New York, 1983), pp. 567–586] and Thompson and Lopes [R. B. Thompson and E. F. Lopes, “The Effects of Focusing and Refraction on Gaussian Ultrasonic Beams,” J. Nondestruct. Eval. 4, 107–123 (1984)] and with experimental results. [Work supported by the U. S. Department of Energy, Office of Energy Research, Office of Basic Energy Sciences, under DOE Contract No. DE‐AC07‐76ID01570.]