By using the conformal mapping method, the elastic interaction between a screw dislocation dipole and an interfacial crack emanating from a semi-elliptic hole was investigated. The complex potential and stress field were derived. The stress intensity factor, crack extension force, strain energy, image force and image torque on the dipole were obtained from the stress field. As well as a translation of the dipole, caused by the image force on the dipole center, an image torque which acted upon the dipole center was also important. Both the translation and rotation had to be considered in static equilibrium. The stress intensity factor at the crack tip was strongly affected by both the dipole orientation and by the angle of the dipole center. The stress intensity factor at the crack tip was reduced when the crack was blunt.

Elastic Behavior of Dislocation Dipoles near a Blunt Crack. Y.S.Yang, S.L.Lee, B.T.Lan: Engineering Fracture Mechanics, 1995, 52[1], 83-93