The elastic interaction between a wedge disclination dipole and collinear interfacial cracks in bimaterials was investigated. The general solutions of complex potentials to this problem were presented by using complex potential theory. As illustrative examples, the closed-form solutions for a wedge disclination dipole interacting with a finite interfacial crack and a semi-infinite interfacial crack were obtained. The stress intensity factors at the tips of the crack and the force acting on the disclination dipole center were also given. The shield and anti-shield effect of the wedge disclination dipole upon the stress intensity factors was evaluated, and the equilibrium position of the disclination dipole was analyzed for various crack geometries and material mismatch. The results indicated that the shielding or anti-shielding effect to the stress intensity factors increased acutely when the disclination dipole approaches the tip of the crack. If the center of the dipole was fixed, there always exists a critical value of angle of the dipole arm which the shielding or anti-shielding effect to the stress intensity factor was maximal. In addition, the length of the dipole arm and the material mismatch have significant influence on the stress intensity factors. The results also showed that the interfacial crack always attracted the wedge disclination dipole and an equilibrium position of the disclination dipole could be available near the interface, which differed from the case of a perfect bonded interface, when the dipole approaches the surface of the crack from infinity. The present solutions contained a series of new and previously known results which could be shown to be special cases.

Interaction of a Wedge Disclination Dipole with Interfacial Cracks. Q.H.Fang, Y.W.Liu, C.P.Jiang, B.Li: Engineering Fracture Mechanics, 2006, 73[9], 1235-48