In this research the affect that lubrication at a hole and pin connection has on the fatigue life of a double shear lap joint is studied both experimentally and numerically. The study focuses on the joint middle plate item, which is connected via a central hole to the outer plates by means of a clearance fitting pin, thereby placing the hole in double shear. In the experimental work three identical batches of fatigue specimens, which are made from aluminum alloy 2024-T3, were fatigue tested. In the first batch the surface of the fastener hole was not lubricated whilst the hole in the other two batches was lubricated - each batch using a different lubricant. The three batches of double shear lap joint specimens were fatigue tested and their S-N curves established. The results show that the specimens in which the holes were lubricated have better fatigue lives than the non-lubricated hole specimens. In the numerical study, FE simulations were performed to include hole lubrication effect on the stress distribution by using different friction coefficient at the interface of the hole and its fastener (pin). The FE results have helped to gain an understanding of the reasons for fatigue life improvement and also have helped to quantify the level of improvement.
- Double shear lap joints - Double-shear - Fastener holes - Fatigue life - Fatigue life improvement - Fatigue specimen - FE-simulation - Finite elements - Fretting - Fretting fatigues - Friction coefficients - Lap joint - Lubrication effect - Numerical studies - Pin connections - S-N curve - Stress distribution