Multiscale modeling and prediction of bonded joint failure by using an adhesive process zone model

In this work, a three-dimensional multiscale adhesive process zone model (APZM) is used to simulate dynamic failure process of bonded joint structures. APZM combines the ideas of the cohesive zone model (CZM), the Cauchy–Born rule, and the so-called virtual internal bond (VIB) theory to predict failures of bonded joints that involves adhesive failure, cohesive failure, and mixture of both. The proposed APZM has some unique advantages to describe mechanical behaviors of bonded joints under general loading conditions. First, in contrast to conventional FEM model, APZM model can simulate dynamic fracture process of structure without remeshing. Second, APZM replaces the ad-hoc traction–separation laws of interface used in CZM with full three-dimensional interphase model, which is based on the VIB theory. Consequently, APZM can naturally capture both mixed failure modes as well as mixture failure mode under complex loading conditions. Third, an empirical elastic energy density function for macromolecular polymers was constructed, and its material parameters are obtained by calibrating the model with material properties measured from experiments such as under pure tension and shear tests. In order to validate APZM model and to predict stress field in adhesive layer accurately, a series of numerical simulations of bonded joints under shear, tension and mixed loading conditions have been conducted. The numerical results indicate that APZM can accurately predict the failure modes as well as the dynamics fracture process of bonded joints.