Crack tip energy release rate for a piezoelectric compact tension specimen

A theoretical fracture mechanics for brittle piezoelectric materials is sum marized consistent with standard features of elasticity and dielectricity. The influence of electric held and mechanical loading is considered in this approach and a Griffith style energy balance is used to establish the rele vant energy release rates. Finite element results are given for a compact t ension specimen having properties consistent with the piezoelectric materia l PZT-4. The influence of the crack opening displacement on the electric fi eld adjacent to the crack is considered. Observations of fracture behavior in a compact tension specimen composed of PZT-4 obtained by park and Sun (J . Amer. Ceram. Sec. 1995;78:1475-1480) are used to assess the relevance of the theoretical results. (C) 1999 Elsevier Science Ltd. All rights reserved .