Crack amplification and shielding in plane piezoelectric solids

A general solution is derived for the problem of a microcrack near the tip of a semi-infinite main crack in a two-dimensional piezoelectric medium. Th e interaction problem is treated by extending the method of pseudo-traction s, which was used in the study of crack-interaction problems in elastic sol ids, to include the pseudo-electric displacements along the microcrack. An algebraic equations system is obtained to determine the unknown pseudo-trac tions and pseudo-electric displacements. The accuracy of the present formul ation is confirmed by the comparison of the present solutions with those re ported in the literature for the limiting cases of isotropic elastic solids . Numerical results for the field intensity factors and the mechanical stra in energy release rate at the crack tips are presented to show the influenc e of various loading conditions, and the location and orientation of a micr ocrack on main crack-microcrack interaction. Amplification or shielding eff ects for the main crack may be introduced due to the presence of a microcra ck. Electric loading is shown to play an important role in crack-interactio ns in piezoelectric solids. The present formulation can be easily generaliz ed to the case of multiple microcracks near the tip of a main crack. (C) 20 00 Elsevier Science Ltd. All rights reserved.