EXACT-SOLUTIONS OF PIEZOELECTRIC MATERIALS WITH MOVING SCREW AND EDGE DISLOCATIONS

The authors in this paper obtain the exact solutions of moving screw and edge dislocations for a hexagonal piezoelectric material by using the eigenstrain theory, which is widely used for elastic materials. From these solutions, one can obtain many meaningful insights of coupling characteristics between mechanical and electric fields for piezoelectric materials. The results show that the decoupled theory, which neglects piezoelectric constants, yields large errors for the mechanical displacement and the electric potential in the piezoelectric material. In addition, the displacement distribution can be obtained exactly by measuring the electric potential distribution. Moreover, the displacement can be totally controlled by applying a certain external electric potential. All these properties are shown by three frequently used piezoelectric materials PZT-4, ZnO, and CdS.