Collinear permeable cracks between dissimilar piezoelectric materials

In this paper, the generalized two-dimensional problem of collinear interfacial cracks, between two dissimilar piezoelectric media subjected to piecewise uniform loads at in®nity, is studied by means of the Stroh formalism. It is di€erent from the relevant analysis done by other authors that in the present work, cracks are considered to be traction-free, but permeable slits across which both the normal component of the electric displacement and the tangential component of the electric ®eld are continuous, and thus avoiding the common assumption of electric impermeability. According to the above continuous conditions combined with the principle of analytical continuation, the considered problem is reduced to a Hilbert problem. Explicit, closed-form expressions for the electric ®eld inside cracks, complex potentials in piezoelectric media and ®eld intensity factors near the crack tips are obtained. These results show that the electric ®eld inside cracks is dependent on the material constants and the applied loads. It is also shown that all the ®eld singularities are dependent only on the applied mechanical loads, not on the applied electric loads, which is di€erent from those results based on impermeable crack mode