Fatigue performance of adhesively bonded single lap joints with non-flat sinusoid interfaces

The role of a sinusoid interface shape on the load bearing capacity and fatigue life of adhesively bonded single lap joints (SLJs) was investigated numerically and experimentally. Aluminium adherends with wavy interfaces were tested under both quasi-static and fatigue loading conditions. The experimental results showed that the non-flat SLJs were indeed much stronger than the conventional flat joints. In order to fully demonstrate the advantage of the non-flat sinusoid SLJ over the conventional SLJ, comparative fatigue tests with different loading levels were performed to determine the durability performance of the SLJs with non-flat interfaces. The experimental results revealed that the non-flat SLJ had considerably higher fatigue life than the conventional lap joint.