Elastic Wave Scattering from an Interface Crack in a Layered Half Space Submerged in Water

ELASTIC WAVE PROPAGATION M.F. McCarthy, M.A. Hayes, (Editors) © Elsevier Science Publishers B.V. (North-Holland), 1989

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Elastic Wave Scattering from an Interface Crack in a Layered Half Space Submerged in Water

D. B. Bogy Department of Mechanical Engineering University of California, Berkeley CA 94720 and S. M. Gracewski Department of Mechanical Engineering University of Rochester, Rochester, NY 14627 The analytical plane strain solution of time harmonic elastic wave scattering by an interface crack in a layered half space submerged in water is presented. The solution of the problem leads to a set of coupled singular integral equations for the jump in displacements across the crack. The kernels of these integrals are represented in terms of the Green's functions for the structure without the crack. Analysis of the integral equations yields the form of the singularities of the unknown functions at the crack tip. These singularities are taken into account to arrive at an algebraic approximation for the integral equations that can then be solved numerically. Numerical results are presented for plane waves incident from the liquid onto the solid structure and for an incident Gaussian beam. The study is related to the use of ultrasonic techniques for detecting interface cracks in layered elastic media.

Published as "Elastic Wave Scattering from an Interface Crack in a Layered Half Space Subof merged in Water: Part II: Incident Plane Waves and Bounded Beams," ASME Journal Applied

Mechanics,

Vol. 53, 1986, pp. 333-338.