FEM Simulation of the Spot Welding Process (Report II) : Effect of Initial Gap and Electrode-type on Nugget Formation and Expulsion(Mechanics, Strength & Structure Design)

概要

論文の詳細を見る
A procedure is developed to estimate expulsion occurrence in spot welding based on the theoretical analysis and FEM. The expulsion will occur when the nugget radius is larger than the contact radius between plate to plate. The nugget formation and expulsion occurrence of a high tensile carbon steel were analyzed for spot welding with initial gap and three type electrodes, Dometype, R-type (40mm) and R-type (100mm). Conclusions show that the nugget formation is greatly affected by initial gap and electrode type. The initial gap affects not only the static contact but also the kinetic contact. The initial formation of the nugget is advanced by the initial gap for the Dome-type electrode and R-type (40mm) electrode. However, the initial formation of the nugget is delayed by the initial gap for the R-type (100mm) electrode when the initial gap exceeds 2.0mm. The effect of the initial gap on the nugget radius at 12 welding cycles is small for Dome-type and R-type (40mm), but large for R-type (100mm) electrodes. The expulsion occurrence is affected by initial gap and electrode type. The expulsion occurrence increases with an increase of initial gap. The expulsion occurrence of the R-type (100) electrode is less than that of the R-type (40mm) and Dome-type electrode. The expulsion occurrence is almost the same between Dome-type and R-type (40mm) electrodes.
大阪大学の論文