Fatigue characterization of polyethylene under mixed mode I/III conditions

Mixed mode I/III fatigue fracture behaviour of bulk polymers is scarcely investigated. Thus, the aim of this work is to focus on the comparison of pure mode I and mixed mode I/III fatigue loading of polyethylene. During mixed mode I/III testing, both increases and decreases of lifetime were observed, depending on the levels of applied mode I and mode III loading. Additionally, the critical influence of friction and the accompanying increase of local temperature between the shear loaded crack flanks in mode III, as well as the dominant fracture mechanisms were discussed based on the fracture surface morphology.