INTERACTION BETWEEN A SCREW DISLOCATION AND A CIRCULAR COATED INCLUSION WITH AN INTERFACIAL RIGID LINE IN PIEZOELECTRIC MATERIALS

The problem of the electroelastic coupling interaction between a screw dislocation and a circular coated inclusion with an interfacial rigid line in piezoelectric solids is investigated. Utilizing the complex variable method, the explicit series form solutions of the complex potentials in the matrix, the coating layer and the inclusion regions are derived. Based on the obtained complex potentials, the image force on the screw dislocation is then calculated by using the generalized Peach-Koehler formula. The image force and the equilibrium position of the dislocation are discussed in detail for various rigid line geometries, coating layer thicknesses and piezoelectric material property combinations. The main results show that, when the length of the rigid line reaches a critical value, the original direction of the image force may be changed for the case of the soft inclusion and coating layer. The screw dislocation is attracted first then repelled by the inclusion and the rigid line leading to a stable equilibrium position when the dislocation approaches the coated inclusion from infinity. For the case of the stiff inclusion and coating layer, the dislocation is always repelled by the inclusion and the impact of the rigid line on image force is a little.