Failure load analysis in single lap joints - effect of adherend notching

In the present study, the failure load improvement obtained from adherend notching for adhesive single lap joints (SLJs) is studied. In the first step, a finite element (FE) analysis is employed to investigate the influence of different adherend notch parameters including the notch width and the notch depth on the adhesive behavior. Then, the peel, shear, longitudinal and von Mises stress distributions in the adhesive mid-plane layer are compared for different adherend notch parameters. In the next step and based on the numerical results, four values of notch depth are selected to perform experiments. For each notch configuration, one ductile and one brittle adhesive are considered. The results demonstrated that the failure load improvement due to the adherend notching is dependent on both the notch depth and the mechanical properties of the adhesive material. For instance, the average value of the failure loads in SLJs containing a brittle adhesive and a notch depth ratio of 20% was improved about 100% while the improvement in SLJs with a ductile adhesive with the same notch depth was about 25%.