Effect of spew adhesive and beveling substrate geometrical shape on stresses in a bonded single lap joint

Abstract

The use of adhesively bonded joints in place of traditional joining techniques such as bolted or rivet joints is becoming greatly popular in recent years. Analytical solutions were used for the evaluation of shear and peel stresses in the adhesive of the single-lap joint. To verify the analytical solutions, three-dimensional finite element models of the single-lap joint were developed to determine the stress distribution under simulated applied loads, .using the software Abaqus. The reduction in peak stresses, however, is not only related to the presence of spew, but also to the shape and size of the spew. Furthermore, the geometry of beveling substrates affects the peak stresses and stress distributions in adhesively bonded single lap joints. Three spew and beveling geometries were considered in this study. The geometries include full triangular spews extend from the bottom of the unloaded end of substrate 1 completely across to the loaded end of substrate 2. Two types bevel were considered, one is on the outside and the other on the inside. The analytical and FEA results were in good agreement and proved suitable for single lap joints. The outside beveling substrate have a significant impact on the peel stress reduction in single-lap joints and should not be neglected in the stress analysis. The combination of the beveling substrates with the spew adhesives leads to reduce peak stress concentrations at both ends of the bonding region and therefore increases the joint strength. The presence of bevel and spew shape geometries in the single lap joint causes the largest percent reduction in peel and shear stresses at the ends of the overlap.