Most piezoelectric materials are brittle. And determination of stress intensity factor is important because piezoelectric material often has defect such as crack or notch. There has been considerable research on the stress concentration and singularity for piezoelectric materials by using theoretical and numerically analysis method. But determination methods of the stress intensity factor for piezoelectric materials have not been fully-established because of difficulty of mechanical handing of piezoelectric material. In this study, we focused on similarity of analytical theory between piezoelectric materials and anisotropic materials. Based on that similarity, this analysis derived the similar general solutions for piezoelectric materials and anisotropic materials subjected to arbitrary loads at the crack or elliptical boundary. And it was shown that theory of anisotropic material was applicable to piezoelectric material by adequately replacing material constants. Furthermore, the extrapolating method on strain of piezoelectric material from experiment of anisotropic materials was discussed.
