Diffraction of Elastic Waves by a Surface Crack on a Plate

Abstract

The interaction of time harmonic elastic waves with an edge crack in a plate is studied. The crack is assumed to be normal to the plate surface and its depth small compared to plate thickness. Only plane strain deformations are considered. The incident waves are assumed to be either plane body waves (compressional (P) or inplane shear (SV) ) of arbitrary angle of propagation or surface Rayleigh waves propagating at right angles to the crack. For each incident wave type the complete high frequency diffracted field on the plate surface is calculated. Solution is obtained by the application of an asymptotic theory of diffraction. Application to ultrasonic inspection techniques is indicated.