Polymer interfacial fracture simulations using cohesive elements

Abstract

A family of cohesive elements is presented based on cohesive zone models to describe polymer interfacial fracture. Their capabilities are demonstrated in three case studies of interfacial failure. The first is a simulation of the t-peel test for the determination of adhesion between two elastomers. This case is characterized by large, inelastic deformation that is difficult to model using classical fracture mechanics and analytic cohesive zone approaches. The formulation allows simulation of crack growth in the presence of large global strains and the identification of peak viscous loss zones in the peel arms. The second case study is the analysis of a compressive shear test to determine adhesion between a viscoelastic elastomer and a rigid substrate. An experimentally observed transition from stable to unstable fracture is described accurately by the model, providing appropriate cohesive zone parameters are established. The third example treats interfacial failure in a multilayer elasto-plastic polymer system. The approach illustrates a capability to capture crack nucleation and propagation in systems with complex microstructures comprising of multiple layered phases and associated interfaces.