Investigation of internal step and metal part reinforcement on joint strength in the adhesively bonded joint: Experimental and numerical analysis

Abstract

Many studies have been performed to increase the failure load of adhesively bonded joints, which enable different types of materials to be joined together for use in the aerospace and automotive sectors. In studies from published literature, various methods have been used to increase the failure load of joints, such as altering the joint geometry, investigating additives to the adhesive or changing the overlap area parameters. This study experimentally and numerically investigated the mechanical properties of single lap joints obtained by applying internal steps of different lengths to the overlap region of the joints and adding metal pieces of different lengths. In the study, adhesive bonded single-lap joints were produced by using DP460 liquid structural epoxy as the adhesive, AA2024-T3 aluminum alloy as the adherend and AISI 1040 steel as the metal piece. As a result, the internal step lap joint (ISLJ) and metal piece reinforced lap joint (MRLJ) type was found to carry more load than single lap joint (SLJ) type. Also, the change in the step length in the ISLJ and the metal piece length in the MRLJ type had a significant effect on the failure load of the joint. The ISLJ and MRLJ geometry carried about 26–60% and 17–41% more load than the SLJ geometry, respectively. When the failure loads obtained in the experiments and the numerical analysis were examined, it was concluded that their results were quite compatible with each other when the cohesive zone model was used in the numerical analysis.