Investigation of the relationship between the length of the joint and the damage load of the joint in the adhesively bonded step lap joints

One of the often preferred bonding methods is the adhesive bonding method because of the great advantages of combining composite or different types of materials used in the aerospace, space and automotive industries. The type of connection that is often used in the method of bonded with adhesive is the single-lap joint connection type. Single-lap joints, due to eccentric loading, peel stresses that cause damage to the ends of the overlap zone are formed and different connection types are used to reduce these stripping stresses. One of these connection types is the type of stepping lap connection obtained by opening the steps to the overlap zone. In this study, have the same bonding area, single lap overlap joint, single step lap overlap joint and have the five different step length three step lap overlap joints types mechanical properties are experimentally and numerically investigated. In the experimental study, AA2024-T3 aluminum alloy as adherend material, the two-component DP460 structural adhesive is used as adhesive. As a result, the connection type to the three-step carries more load than other connection types. In addition, the change in the step length of the three-step joints type to has a significant effect on the damage load of the connection. When the damage loads obtained from the experiments and numerical analysis were examined, it was concluded that using the cohesive zone model in numerical analysis and the results of experimental and numerical analysis were quite compatible with each other. Another result obtained in the study is that the approximate optimum length of the first stage opened at the ends of the overlap zone in the three-step lap joints is obtained.