Resonant frequencies of the scattering of elastic waves by three-dimensional cracks

The diffraction of elastic waves by three-dimensional cracks of arbitrary c ross-section is investigated. Using an earlier method [1] for solving the r esulting systems of integral equations, the dependence of the resonance sca ttering frequencies on the crack shape is analysed. The numerical results i ndicate that the crack shape has a noticeable effect on the distribution of resonance poles in the complex frequency plane. In theory, this means that the information obtained can be used to solve inverse problems of flaw det ection (determining the size and shape of a crack from the reflected signal ). (C) 1999 Elsevier Science Ltd. All rights reserved.