Scale effect on migration and coalescence of void in piezoelectric film subjected to gradient stress and electric fields

In this paper, an analytical method is presented to solve the scale effect on migration motion and coalescence of void in piezoelectric solid subjected to gradient stress and electric filed. The piezoelectric solid is considered as an infinite orthotropic piezoelectric film corresponding to the scale of void. The surface diffusion of void in piezoelectric film is taken as the dominant mechanism for the migration motion of the void. Based on the non-local elastic theory considering the interact force among atoms, the influences of small-scale parameter, stress gradient, stress state, electric loading, and shape of void on the migration motion coalescence of void in piezoelectric film are described.