Intensity factors for some common piezoelectric fracture mechanics specimens with conducting cracks or electrodes

Abstract

This paper provides the stress and electric field intensity factors for some common piezoelectric fracture mechanics specimens with electrically conducting cracks or electrodes. Firstly, the solution for a vertical crack with electrically conducting boundary condition on its surfaces is established for a piezoelectric strip under combining mechanical and electrical loads. Then, a surface-cracked strip, a double edge cracked strip, and a center-cracked strip, subjected to uniform stress and electric field loads simultaneously, are investigated. Also investigated is an edge-cracked strip under pure bending and uniform electric field loads. The influence of piezoelectric effect on the stress and electric field intensity factors is found to be insignificant, suggesting that the stress intensity factors of piezoelectric materials under mechanical loads can be obtained in a same way as ordinary brittle solids, and the electric field intensity factors of piezoelectric materials under electric field loads can be obtained in a same way as ordinary dielectrics. However, the results show that the mechanical loads can produce electric field intensity factors, and the electric field loads can produce stress intensity factors in piezoelectric materials, due to the fact that the medium has finite size.