CRACK EXTENSION FORCE IN A PIEZOELECTRIC MATERIAL

A conservation law that leads to a path-independent integral of fracture mechanics is derived along with the governing equations and boundary conditions for linear piezoelectric materials. A closed-form solution to the antiplane fracture problem is obtained for an unbounded piezoelectric medium. The path-independent integral is evaluated at the crack tip to obtain the energy release rate for a mode HI fracture problem. For a fixed value of the mechanical load, it is shown that the crack growth can be either enhanced or retarded depending on the magnitude, the direction, and the type of the applied electrical load. It is also shown that, for certain ratios of the applied electrical load to mechanical load, crack arrestment can be observed. © 1990 by ASME.