An approach for analysis of poled/depolarized piezoelectric materials witha crack

In this paper, the influence of dielectric medium inside a crack, on crack growth, in an infinite poled or depolarized ceramic. has been studied by em ploying an electric boundary condition derived from the exact boundary cond itions proposed by Sosa ( 1996). The effect of remanent polarization has al so been examined. The results obtained show that electric displacement on c rack surfaces is not always zero. Hence, for studying fracture problems of piezoelectric ceramics with cracks accurately, the exact boundary condition s should be implemented. In addition, the results indicate that the effect of remanent polarization is equivalent to that of a positive electric field and it cannot be neglected. It is also found that a positive electric fiel d always has a tendency to open a crack, and a negative electric field tend s to close a crack.