Competitive fretting fatigue failure analysis of Al alloy-CFRP riveted and adhesive-riveted single-shear lap joints

Fatigue tests on Al alloy-carbon fibre reinforced plastic (CFRP) single-shear lap riveted joints and adhesive-riveted hybrid joints are conducted to reveal the failure mechanisms of joints under different loads. The novelty of this study is that the effect of heat accumulation caused by interfacial friction on joint competitive failure is considered. Results show that the Al-CFRP joint is a typical competitive fretting fatigue, and the failure modes of heterogeneous joints are affected by the sensitivity of the mechanical properties of materials due to the external environment change. The failure location of the joint under low load is the Al plate. As the load increases, the joint enters a gross slip state accompanied by a temperature rise. In addition, the performance of the CFRP decreases significantly, leading to the fracture of the CFRP plate. The existence of the adhesive slows down the interfacial wear, which can improve the service life by 500% under lower loads, but it cannot prevent the temperature rise under higher loads and only improves the life by 80%. When selecting life-enhancing methods in engineering applications, the hybrid joint can be considered under low loads, and high-temperature-resistant composites are recommended under high loads.