The collective dislocation behavior near a crack tip in a ductile layer sandwiched between two brittle solids was analyzed via two-dimensional dislocation dynamics simulations that incorporate a cohesive zone model. The cohesive crack tip was treated as part of a much larger finite crack confined in the ductile layer. The underlying boundary value problem was formulated with a set of boundary integral equations and numerically evaluated with a collocation method. The fracture energy of the layered composite material was shown to be strongly correlated with the layer thickness and was directly influenced by the cohesive strength of the ductile layer.

A Combined Dislocation-Cohesive Zone Model for Fracture in a Confined Ductile Layer. N.C.Broedling, A.Hartmaier, H.Gao: International Journal of Fracture, 2006, 140[1-4], 169-81