A refined calculation of V(z) and V(z, x0) curves is presented for a line-focus acoustic microscope and for a specimen which contains a discontinuity normal to its free surface. In the context of a Fourier integral approach, more accurate expressions are employed for: (1) the angular spectrum of the field produced by the lens; (2) the voltage response of the transducer; and (3) the reflection coefficient of the object. In addition, the usual "thin" lens theory has been extended to "thick" lens theory. For V(z, x0) details are given for the case of a surface-breaking crack, and the inverse problem of determining the Rayleigh-wave reflection coefficient of a crack has been solved in an approximate manner. Comparisons between theoretical and experimental results are presented fpr the case that the discontinuity is the edge of the specimen. The reflection coefficient calculated from experimental results agrees well with the theoretical value.
ASJC Scopus subject areas
- Physics and Astronomy(all)