Studies on the stress distribution and fatigue behavior of weld-bonded lap shear joints

The construction and hardness distribution of weld-bonded lap joints were investigated, and a computational model for weld-bonded joints was established on this basis, which consisted of the four parts of the base metal, the heat-affected zone, the nugget and the adhesive layer. Stresses in weld-bonded joints were computed and compared with those in spot-welded and adhesive-bonded joints. Fatigue tests were carried out on these three types of joints to study the fatigue behavior and fracture characteristics of the joints. Results showed that stresses from numerical analysis agree well with experimental results and observed phenomena. The application of adhesives in spot welding greatly improves the joint fatigue performance, while the presence of weld spots in adhesive-bonding has a negative effect on the joint fatigue performance.