Electromechanical interaction of a two-phase eccentric piezoelectric circular fiber having electromechanical interface damage with a straight piezoelectric screw dislocation

In the design of certain electromechanical systems, the study of the interaction of piezoelectric line defects with imperfect electromechanical interfaces and piezoelectric inhomogeneities is of interest. This work, firstly considers an infinitely extended piezoelectric matrix containing a straight piezoelectric screw dislocation near an embedded two-phase piezoelectric inhomogeneity made of a core circular piezoelectric fiber eccentrically covered by a piezoelectric coating. Secondly, by applying a simple limiting procedure to the above-mentioned configuration the new configuration of a piezoelectric screw dislocation and a single piezoelectric fiber located on opposite sides of the straight wall between two piezoelectric half-spaces is modeled. In both the first and the second problems, in general, each phase may have an electromechanically imperfect interface with its adjacent phase. The degrees of mechanical and electrical interface damage are modeled analytically by the concepts of the interface spring stiffness and the interface capacitors, respectively. These problems are treated analytically by the utilization of the complex vector potential functions, conformal mapping, and Laurent’s series expansion. The effects of the degrees of the electromechanical damage at the interfaces, the amount of the nonuniformity of the fiber coating layer in the case of the first configuration, the distance between the fiber and the straight wall in the second configuration, and the electromechanical properties of the phases on the electromechanical image force and the stable and unstable equilibrium positions of the dislocation are examined. In some limiting cases, the current analytical solution is verified with the existing results in the literature.