ENERGY-RELEASE RATE ASSOCIATED TO A CRACK PROPAGATING ALONG A CURVILINEAR INTERFACE

We consider the antiplane problem set in a two-dimensional domain cons isting of two different materials separated by a regular curvilinear i nterface. It is assumed that a crack is growing along the interface. T he variational problem is expressed first in the local reference frame associated to the interface, then the expression of the energy releas e rate is derived using the so-called theta-method. It is shown that i n addition to the classical term, there is a term related to the deriv ation of the local metric associated to the interface, involving the 3 rd derivative of the map. Finally, it is shown that the energy release rate depends an the theta value at the crack front only.