Effect of Stacking Sequence on Fatigue Performance of CFRP–Al Single-Lap Adhesive Joints: Experimental Study

This study aimed to explore failure mechanisms of carbon fibre-reinforced plastic (CFRP)–aluminium (Al) single-lap adhesive joints which CFRP adherends had different stacking sequences. These results showed that fatigue performance of CFRP decreased as the number of 45° plies increased, which caused the initial failure location to gradually move from the adhesive layer towards the CFRP. Under high load levels, joint-failure models were influenced by the stacking sequence of CFRP; large-area cohesive failure occurred in joints when the CFRP stacking sequence was [0/90](4s) and [0/45/−45/90](2s), and delamination failure occurred when the CFRP stacking sequence was [45/−45](4s), due to the weak interlaminar properties of CFRP. However, under low load levels, the stacking sequence of CFRP had little effect on the failure model of the joint, with interfacial failure being the main failure mode for all joints due to weakening of the mechanical interlock.