A study on the shunt effect in resistance spot welding

Abstract

One of the important factors affecting the weld quality of practical resistance spot welding is the shunt effect, which deteriorates weld quality due to the shunt current that flows through neighboring welds. Although some experimental studies for compensation of its effect have been presented, no effort has been made to establish an analytical model that can predict the effect of shunt mechanism on the weld quality. This paper presents an analytical model by which the shunt effect upon the nugget growing behavior can be analyzed. The voltage field and temperature distribution in the weldment are computed by the proposed three-dimensional finite difference numerical model. Experimental verification of the calculated results was also performed and discussed in detail. The comparison of both results shows that the proposed thermal-electric model can predict the shunt effect fairly well.