Effect of carbon fibres on the static and fatigue mechanical properties of fibre metal laminates

It is crucial to understand the characteristic fatigue crack initiation and its growth mechanisms, as well as the relationship between the mechanical properties and the fatigue damage evolution in fibre metal laminates (FMLs). Two types of FML were studied in this work: a polyacrylonitrile-based carbon fibre epoxy matrix composite sandwiched by Ti-6Al-4V (Ti-alloy) sheets (IMS60-Ti) and a pitch-based carbon fibre epoxy matrix composite sandwiched by Ti-alloy sheets (K13D-Ti). The static and fatigue mechanical properties of IMS60-Ti and K13D-Ti were investigated. The increased failure strain of the FML was greater than that of carbon fibre-reinforced polymer (CFRP) matrix composites. The fatigue life of IMS60-Ti was much longer than that of K13D-Ti. The fatigue damage process in IMS60-Ti was related to the fatigue creep behaviour of the Ti-alloy face sheet and mode II cracking at the CFRP/Ti-alloy interface, and the damage in K13D-Ti was related to the K13D CFRP laminate.