Analysis of dynamic crack propagation using a time-domain boundary integral equation method

Presented in this paper is a boundary element method which enables the simulation of dynamic crack propagation under arbitrary loading conditions and without any a priori assumptions regarding the crack path. The direction and speed of crack advance are controlled only by a fracture criterion. Fast crack growth is investigated in an unbounded linear elastic body under plane strain or longitudinal shear. For in-plane deformation under mixed mode loading the influence of crack closure on the computed crack path is considered by solving the related contact problem. The starting point is a non-hypersingular time-domain traction boundary integral equation. A collocation method in conjunction with a time-stepping scheme is applied to solve the integral equation numerically. The accuracy of the numerical method is checked by comparison with analytical solutions available for simple situations. Some examples of curved cracks propagating with variable speed in inhomogenous stress fields serve to illustrate the versatility of the method.