Failure Mode Prediction of Single Lap Bolted Joints

In this paper, the failure mode of bolt clamped single lap joints of aluminum alloy 2024-T3 have been studied using numerical finite element method. To do so, a 3D model according to the available experimental fatigue test specimens has been created and the stress and strain analysis has been carried out using finite element based package. The stress distribution, contact details such as pressure and slip amplitudes have been employed to study the failure modes such as tensile failure or fretting fatigue. The results have been compared to the available experimental fatigue tests results. The numerical results show that in low applied clamping forces, the fatigue failure of the specimens occurs around the stress concentration location without wear but when the clamping force increases, the fatigue life increases and the cracks nucleate and propagate far from the hole edge because of fretting fatigue. Also, with the further increase of clamping force, the fatigue life reduces due to occurrence of the fretting fatigue in the critical location where the slip amplitude is within its critical region and the fretting failure occurs earlier than tensile failure.