DIFFRACTION OF SH-WAVES IN A LAYERED PLATE.

The study of the diffraction of elastic waves at an obstacle or discontinuous structures is of considerable importance in elastodynamics. The authors set up and solve the diffraction problem of SH-waves travelling in a layered plate and normally incident on a plane crack. Such a crack can be formed due to some manufacturing defect causing loose coupling of the layers rather than perfect bonding. The method is based upon D. S. Jones' modification of the Wiener-Hopf technique and the transmitted waves in the two regions separated by the crack are shown to satisfy dispersion relations appropriate to the geometry of the medium of transmission resulting from the crack. 7 Refs.