Elastodynamic Stress-Intensity Factors for Tearing of a Half Plane

This paper is concerned with the propagation of a crack which emanates under an arbitrary angle from a free surface, when that surface is subjected to antiplane mechanical disturbances. The elastodynamic problem is solved by the method of homogeneous solutions, which is based on the observation that for the externally applied disturbances that are considered here the particle velocity is self-similar. The shear stress in the vicinity of the crack tip is determined, and a stress-intensity factor is computed. For various values of the crack propagation velocity the dependence of the stress-intensity factor on the angle of crack propagation is studied. As the velocity of crack propagation increases, the maximum value of the stress-intensity factor is still obtained for symmetrical crack propagation. The singularities at the corners of the wedge-shaped regions neighboring the propagating crack are also examined. It is shown that for small values of the crack propagation velocity, the elastodynamic results reduce to corresponding quasi-static solutions.