Investigation of different parameters on the performance of single lap joints

Abstract

The efficiency of the machines have become key point for competition among automotive and aircraft industries. In order to reduce the fuel consumption and increase the efficiency, industry has a huge focus on development of lightweight materials with the comparative performance to the traditional metals. Fiber reinforced plastics, while being light in weight and having high load bearing capacities are often used in place of traditional sheet metal components in the body shop. In real life applications, different components needs to be joined together to perform the desired function. Mechanical joints generally incur low cost and facilitates easy disassembly for the maintenance without damaging the basic components. Bolt torque, washer and geometry of the joint are the important parameters, which affects the performance of the joint. Therefore, to analyse the effects of aforesaid parameters, the present study deals with experimental and numerical investigations on failure analysis of the single lap single bolt joint under tensile loads. For manufacturing composite laminates, 2D woven glass fiber has been used as reinforcement in the epoxy. Two different levels of torque i.e., 0 Nm and 5 Nm were used to analyse the effect of bolt pretension on the joint performance. To study the effect of washer size on the failure behaviour, outer diameter of the washer was varied from 12 mm to 16 mm. The geometric parameters i.e., w/d and e/d have been varied from 3 to 5 and 3 to 4 respectively. From the experimental results, increasing the initial bolt pretension and w/d ratio has shown increase in the failure load of the joint. However the efficiency of the joint decreases with increase in w/d ratio. It was observed that the stiffness of the bolt joint increases by reducing the outer diameter of the washer. Increasing w/d ratio has shown a positive effect on the joint stiffness. For numerical analysis, characteristic curve method along with Tsai-Wu failure criteria has been used in the ANSYS software. There was a good agreement between the numerical and experimental results.