When does an adhesively bonded interfacial weak zone become the nucleus of a crack?

The conditions under which an adhesively bonded weak zone (with continuously distributed adhesive forces) at the interface between two dissimilar elastic half planes can become the nucleus of a crack are derived. The problem is ®rst reduced to a traction-free weak zone at the interface between two dissimilar elastic half planes, subjected remotely to an inhomogeneous stress ®eld. This reduction procedure allows the general solution to be obtained in ordinary functions without the usual Cauchy integrals