Sensitivity of Solid Element Spot Weld Modeling Methodology to Nugget Diameter

A vehicle’s structure has more than 4000 spot welds, which can be considered as one of the main design criteria that affects the general stiffness as well as the durability of an automobile. Considering the essential role of finite element-based simulations of the spot-welded structures on the design phases of vehicle development, accuracy of analyses can be considered as one of the main concerns to meet the design objectives. This study examines the sensitivity of solid element spot weld modeling technique to nugget diameter. Comparative stress and multi-axial low cycle fatigue analyses are conducted for the inspection of the effect of weld diameter on solid element spot weld simulations. Displacement contours as well as local stress profiles at the vicinity of the spot welds are examined to evaluate the effect of nugget diameter on general stiffness and safety. Multi-axial low cycle fatigue analyses are conducted for the specimens composed of U-profiles, and different thickness levels are simulated for a set of nugget diameters. Simulation results are compared with the low cycle fatigue tests’ life cycles to determine the accuracy of the solid element spot weld modeling methodology and its sensitivity to nugget diameter.