Cohesive zone modeling for viscoplastic behavior at finite deformations

An elastic-viscoplastic cohesive zone model based on the standard continuum description is developed to provide a constitutive framework that considers viscoplastic deformation accompanied by isotropic hardening behavior at finite deformations. By considering the cohesive traction relaxation problem, an analytical solution is obtained to capture the traction decays exponentially at constant displacement jump. An extensive parametric study is also conducted in determining traction–separation response under pure mode loading with various rate-related parameters at different deformation rates. Further, a parameter fitting has been performed, obtaining the parameters of viscoplastic cohesive model from the rate-dependent experimental curves of a DCB test. Results show that the capability of the framework to capture the rate-dependent inelastic behavior of the interface at finite scale.