Three-dimensional dynamic weight functions for mixed-mode crack problems

An indirect boundary element method is developed to analyse three-dimensional elastodynamic fracture mechanics mixed-mode problems. A set of boundary integral equations to determine the fictitious loads and displacement discontinuities are then derived in Laplace transform domain. The stress intensity factors K-zeta*(p) (zeta = I,ll,III) are evaluated by both the equivalent stress method and the weight function method for dynamic loading. The stress intensity factors in the time domain K-zeta(tau) are obtained from the Laplace transform solution by the Durbin inversion method. Results for mixed-mode dynamic stress intensity factors are presented for a square crack in an infinite body, and for a rectangular and a circular crack in a square bar.