Investigation of fracture in polymers using a cohesive zone model

Polymers arc increasingly being used for engineering structures and medical devices because of their excellent corrosion resistance and low cost compared with metals. However, the lifetime of plastics used in severe environments is significantly reduced due to stress corrosion cracking (SCC). The current understanding of SCC in polymers is mostly empirical. In this paper, a methodology for investigating SCC in polymers is presented. The proposed approach, based on the cohesive zone model (CZM), is capable of characterizing the degradation in the fracture zone explicitly, independent from the bulk material. In our preliminary investigation, the fracture of an clastic-plastic material was simulated, and the results were compared to a published data. The simulation outcome indicates that the CZM is an effective tool to study fracturc propagation in polymers under SCC.