Dynamical weight functions for a planar crack

The stress intensity factors are evaluated for a moving planar crack for lo adings which vary arbitrarily in time and three dimensions of space. We exp loit the adjoint elasticity equation obeyed by the corresponding weight fun ctions, and a new and more universal Wiener-Hopf factorization of the Rayle igh function, this beings the central difficulty in such calculations. For the mode a weight function we give further asymptotic results crucial to a subsequent calculation of crack stability with respect to out-of-plane pert urbations.