Influence of geometric and material parameters on the mode II interlaminar fatigue/fracture characterization of CFRP laminates

Abstract The objective of this work is to perform fatigue/fracture characterization of carbon-epoxy laminates under pure mode II loading. The End-Notched flexure (ENF) test was employed to execute quasi-static and fatigue/fracture tests aiming to determine the mode II fracture energy, the fatigue lives and the modified Paris law parameters representative of this material. These Paris law coefficients were used as input in a high-cycle fatigue cohesive zone model that was validated against experimental fatigue lives. Afterwards, the numerical cohesive zone model was employed to assess the influence of several geometrical and material parameters on the mode II interlaminar fatigue/fracture behaviour of Carbon-Fibre Reinforced Plastic (CFRP) laminates. Important conclusions were drawn concerning the fatigue performance of these materials under pure mode II loading.