Elastic interaction between screw dislocations and a microcrack near an elliptic hole

Abstract

The elastic interaction between a screw dislocation and a microcrack near an elliptic hole was investigated. The stress field, the stress intensity factors at both tips of the microcrack, and the image force on the lattice dislocation were derived. The stress intensity factors at the crack tip and the image force on the lattice dislocation were both strongly affected by the elliptic hole, and were dependent on the positions of the lattice screw dislocation, the dislocations existing in the microcrack and elliptic hole, and the geometry of the elliptic hole. If a lattice dislocation arose from the right-hand-side tip of the microcrack by a mode III applied stress, the lattice dislocation had a shielding effect on the propagation of the right-hand-side crack tip, but had an enhancing effect on the movement of the left-hand-side crack tip. It was also found that the dislocations existing in the elliptic hole and microcrack played an important role on the fracture.