Abstract: The local solutions of general displacement fields near a crack of piezoelectric materials are first used to construct a new general displacement modelling of crack problems in piezoelectric materials.With the minimum potential energy principle, a finite element version for piezoelectric materials with a blunt crack is proposed.A new singular finite element is constituted and a new method to calculate the general intensity factors of crack problems in piezoelectric materials is obtained. Compared with theoretical solutions, the results obtained by the present method are in good agreement with those of theoretical ones.The results of the different structural dimensions illustrate that the present method is stable, reliable and highly accurate, high efficient and easy to use in practical program operation.

Key words: piezoelectric material, crack, singular element, intensity factor, electric displacement