Scattering of Elastic Waves by a Plane Crack of Finite Width

A rigorous theory of the diffraction of time-harmonic elastic waves by a cylindrical, stress-free crack embedded in an elastic medium is presented. The incident wave is taken to be either a P-wave or an SV-wave. The resulting boundary-layer problem for the unknown jump in the particle displacement across the crack is solved by employing an integral-equation approach. The jump is expanded in a complete sequence of Chebyshev polynomials, and, writing the Green’s function as a Fourier integral, a system of algebraic equations is obtained. Numerical results are presented in the form of dynamic stress intensity factors, scattering cross sections, and normalized power-scattering characteristics. Some of them deviate from earlier published results.