Damage-based Cohesive Zone Model for Rate-depend Interfacial Fracture

Cohesive zone models (CZMs) are being increasingly used to describe local fracture and failure behaviors in a number of material systems. The idea of the cohesive approach is to include a complex behavior around the crack front into the simple cohesive model for crack propagation analysis. Many cohesive laws have been proposed and there are a few rate-depend cohesive zone models. To describe the damage and failure phenomena on the interface, damage-based cohesive zone model (DCZM) is the most reasonable. Therefore, the aim of this article is to develop the phenomenological rate-depend cohesive zone model based on damage mechanics. Based on the internal variable theory of thermodynamics, a continuum interface constitutive model relating interface traction with interface separation has been developed. By introducing an interface damage variable, an evolution equation was derived to characterize the degradation of interfacial rigidity with interface debonding. This constitutive relation is applied to the matrix cracking in composites materials and the shear stress distribution, interface damage evolution, pullout stress, and pullout works were discussed. These results show that the proposed model qualitatively explain the experimental results and is useful for the prediction of the damage states, remaining strength and life time of the rate-depend bonding interface.