“…In processing of piezoelectric solids, various structural defects such as inclusions and voids in the piezoelectric solid are often generated, which have detrimental influences on the electromechanical coupling function of piezoelectric solid (Gosling and Willis, 1995; Ru, 2000). The migration motion of defects (voids) in solids has been described by means of different methods, where driven mechanisms for the migration movement of voids are surface diffusion and volume diffusion induced by thermal gradient, stress gradient, and electric potential gradient exerted on the solid (Cho et al., 2010; Desai et al., 2010; Pete et al., 2012). An electroelastic analytical method for an orthotropic piezoelectric solid with defects is presented in Sosa and Khutoryansky (1996) and Hou and Yang (1998) in which a general solution is given to describe stress concentrations that arise in the vicinity of circular and elliptical holes, and may be used as the reference to analyse the stress gradient field in orthotropic piezoelectric solid.…”