Characterisation of near pure mode II quasi-static and fatigue delamination behaviour of a carbon–glass interface using a pure-moment-loaded DCB test rig

This work covers the characterisation of delamination growth in a carbon–glass interface, representative of the one in a wind turbine blade. A pure-moment-loaded Double Cantilever Beam (DCB) test rig is used under quasi-static and fatigue loading. A new fatigue characterisation procedure is adopted by real-time controlling the prescribed energy release rate G . This procedure enables sweeping any desired G range at a user-defined rate independently of the compliance of the specimen. A finite element simulation using a cohesive zone model confirms the testing was performed at near pure mode II conditions. From the quasi-static tests, the onset and steady-state fracture toughnesses are characterised. Fibre bridging is observed, which is believed to explain the characterised R-curve effect. From the fatigue tests, Paris’ law is characterised in a wide G m a x range in each test. The characterisation of the quasi-static and fatigue fracture behaviour of the carbon-glass interface is thus successfully achieved. • New static and fatigue near pure mode II characterisation of a bi-material interface. • Tested in pure-moment-loaded DCB test rig, where ERR is independent of crack length. • A novel ERR-controlled characterisation procedure is developed for fatigue tests. • Great R-curve effect, due to large-scale fibre bridging, seen in quasi-static tests. • Numerical calculation of the mode mixity through a cohesive zone J-integral approach.