Abstract
The strength of a stepped-lap bonded joint under tensile shear loading is investigated both analytically and experimentally. The joint used in this study consists of adherends of carbon steel and an adhesive of epoxy resin. The strain and stress distributions were analyzed by applying the finite element method on the assumption of elastic deformation. The stress distributions in butt and lap sections varied remarkably on both edges of the steps. The joint strength was calculated by applying strength laws of three kinds of equation to the stress distributions of corresponding parts in the joint. It was predicted that the strength was smaller at the edge of the butt part than at the lap part in every step corner. The calculated strain distribution and strength values of the stepped-lap joint coincided approximately with the experimental ones. On experimental stress-strain curved of the joint, however, it was observed that the joint was completely broken with the increase of load after the initial cracks occurred at the edges of the butt part.
