INTERACTION BETWEEN A SCREW DISLOCATION AND A CIRCULAR INCLUSION WITH IMPERFECT INTERFACE IN CYLINDRICALLY ANISOTROPIC COMPOSITES

The elastic interaction between a screw dislocations and a circular inclusion with imperfect interface in cylindrically anisotropic solids is investigated. The analytic solutions of complex potentials and elastic fields are obtained by means of the complex variable method. With the aid of the Peach-Koehler formula, the explicit expressions of image forces exerted on the screw dislocation is derived. The influence of the interface imperfection and the material anisotropy on the image force and the equilibrium position of the screw dislocation near the circular interface are discussed. The results show that the screw dislocation is always attracted by the imperfect interface. The dislocation inside isotropic matrix is always repelled by the anisotropic inclusion. When the degree of anisotropy of the inclusion is larger than that of matrix, an unstable equilibrium position of the dislocation near the interface can be found. If the parameter of the interface imperfection is fixed, there is a critical value of the degree of anisotropy of the inclusion to alter the direction of the image force acting on the dislocation.