Engineering Fracture Mechanics | 2021
A rate-dependent cohesive zone model with the effects of interfacial viscoelasticity and progressive damage
Abstract
Abstract A generalized rate-dependent cohesive zone model for describing the interfacial viscoelasticity and progressive damage of mode I fracture is presented. The proposed model has efficiently extended the traditional bi-linear cohesive traction-separation law to remove the assumptions that some of the rate-dependent parameters such as elastic stiffness, initial separation and strength, critical separation are constant at different loading speeds. Furthermore, the rate-dependency of the damage evolution, which is observed in experiments but largely neglected in the previous models, is established to describe the rate-dependent fracture process linked with the generalized traction-separation law, and an equivalent generalized Maxwell model (GMM), based on the Kohlrausch-William-Watts function with significant fewer material parameters required as input, is proposed to describe the time and history dependent stress-strain relationship of the viscoelastic interface material. The proposed model is validated by the simulations of the DCB tests with both the SBR/NR rubber interface and Polyurethane interface.