Strength improvement in single lap adhesive joints by notching the adherends

Abstract

In this study, an easy procedure is proposed to improve the strength of Single Lap Joints (SLJs) by introducing a notch in the adherends right after the overlap length. At first, the effect of different notch parameters on the peel, shear and von Mises stress distributions of the adhesive mid-plane layer is investigated by using the Finite Element (FE) method. The considered parameters are the notch angle, the notch width, the notch depth, and the notch distance from the overlap length. Afterwards, a simple 90-degree notch angle which can be easily manufactured is selected for adherend notching based on the numerical results. In addition, in order to experimentally investigate the effects of different notch parameters on the failure load of adhesive joints, five various notch depths with two different adhesive curing methods are considered. Finally, the experimentally obtained fracture loads are compared with the theoretical ones which are based on the predictions of von Mises stress and peel. The results show that using the adherend notching can significantly improve the load bearing capacity of SLJs. For instance, a simple notch with 20% notch depth ratio can improve the load bearing capacity of the SLJ about 60%.