FEM Simulation of Spot Welding Process (Report III) -Controlling of Welding Current Using Electrode Displacement for Formation of Large Enough Nugget without Expulsion-

摘要

In the case of press formed parts, the gap between lap joints is unavoidable. Normally, the variation in the size of the gap is fairly large. If the variation of the initial gap exceeds certain limits it is difficult to make sound spot welding joints without expulsion. In this report, FEM analysis is employed to study the influence of the initial gap on weldability. The validity of the computed results is examined by comparison with experiments. Generally, the nugget grows faster and the expulsion occurs earlier when the initial gap is large.