SCATTERING OF HYDROACOUSTIC WAVES BY A NARROW CRACK IN AN ELASTIC PLATE

The scattering of waves by an infinite elastic plate, which covers an acoustic half-space and is weakened by a crack in the form of an infin itely long cut of finite width with parallel edges is considered. The scattered field is expressed in terms of the solution of an integro-al gebraic system of equations on the crack. The logarithmic characterist ic of the kernel enables Bubnov's method with a basis containing Cheby shev polynomials of the first kind to be used for the numerical analys is. Particular attention is given to the asymptotic investigation of t he scattering diagram and the amplitudes of the surface waves for a na rrow crack and a thin plate. A comparison with the well-known model of a point crack enables the range of parameters of the problem where th e point model is applicable to be indicated. (C) 1997 Elsevier Science Ltd. All rights reserved.