Analysis of the Reflection of Point Force-Induced Crack Surface Waves by a Crack Edge

Dynamic stress fields near cracks follow in part from the reflection of crack surface waves by the crack edges. To gain insight into the reflection process, the problem of stationary normal and tangential point forces applied to one surface of a stationary semi-infinite crack is considered, and analytical expressions for the crack surface reflection-generated particle velocity waves presented. Study of these expressions shows that the dominant reflected wave is singular at its wave front, travels at the Rayleigh speed, and is generated by the reflection of a singular Rayleigh wave. However, the reflection process “moves” the singularity from the velocity component parallel to the particular force to the component normal to it.