Crack propagation induced by a plane stress wave in a general anisotropic elastic material

The stress intensity factors of a semi-infinite crack propagating with constant speed in an anisotropic elastic solid under a uniform stress wave loading are considered. The crack is assumed to start propagating at some arbitrary time after an obliquely incident plane stress wave strikes the crack tip. It is shown that the stress intensity factor of the propagating crack has the form of the product of a universal matrix function of the crack speed and an equivalent stationary crack stress intensity factor of t∗, which is the time that would have elapsed since the incident wavestruck the crack tip if the crack tip had been always at its instantaneous position. The present result is a generalization of that obtained by Freund for isotropic materials.