Collinear permeable cracks in thermopiezoelectric materials

The generalized 2D problem of N-collinear cracks in a thermopiezoelectric m aterial, subjected to uniform mechanical-electric loading associated with u niform heat flux at infinity, is studied using the extended Stroh formalism . The problem is addressed based on the permeable crack model, i.e., the cr acks are regarded as thin slits with permeable faces and thus the normal co mponents of electric displacement and the tangential component of electric field are assumed to be continuous across the slit faces. Using the continu ous condition, the considered problem is reduced to a Hilbert one. As a res ult, explicit and closed-form expressions for the complex potentials in the material, the field intensity factors near the crack-tips, and the electri c field inside cracks are obtained, respectively. These results show that a ll the field singularities are dependent on the applied mechanical loading and the heat loading, but not on the applied electric loads. It is also fou nd that the electric field inside cracks is linearly variable, which is dif ferent from the results based on the impermeable crack model. (C) 2001 Else vier Science Ltd. All rights reserved.