By using a dislocation model for a surface crack, and images for the free surface, analytical solutions were derived for the interaction between a screw dislocation near to a mode-III (anti-plane shear) surface crack, an internal crack and a moving crack subjected to a dynamic antiplane stress. The distribution densities of the dislocations, as well as the phase lags, were expressed as a system of singular integral equations which contained Bessel functions. By using this approach, the above dynamic problems could be correctly related to each other, and exact analytical expressions for the stress intensity factor at any given frequency could be derived. The effects of wave number, input incident angle, propagation speed and dislocations upon the stress intensity factor were also deduced.

The Dynamic Problems of Cracks Subjected to Incident Shear Waves. I.C.Weng: International Journal of Fatigue, 1999, 21[9], 975-83