2-D scattering by a crack with contact-boundary conditions

Abstract The dynamic contact problem of a two-dimensional crack subjected to an incident wave is solved using a time domain boundary integral equation. There are three possible phases in the contact-boundary conditions, namely, separation, slip contact and stick contact. Considered here are three examples: (i) a pre-opened crack subjected to normal incidence of an L wave; (ii) a pre-stressed crack subjected to normal incidence of an L or T wave; (iii) a crack with frictional contact conditions subjected to an obliquely incident T wave. In these calculations, near field solutions are obtained as well as scattered far-fields. It is shown that the Fourier amplitudes of the higher harmonics of the scattered far-fields may be useful to determine the pre-stress, the frictional coefficient and the initial crack-opening displacement.