Experimental and numerical analysis of shunting effect in resistance spot welding of Al2219 sheets

Abstract

Abstract. Few aspects of shunting effect have been studied so far. Shunting effect in resistance spot welding (RSW) occurs when the electrical current passes through the previous spot welds. Value of this current depends mostly on distance, number, and size of previous spot welds. This will cause some dimensional and metallurgical changes in welding nugget as well as heat affected zone (HAZ). In this study, shunting effect of RSW is considered by finite element method (FEM) and the results are compared to experiments performed on aluminum alloy 2219. Weld spacing together with welding current and time are considered to discover the effect of shunting current in the final quality of nugget. A three factor experiment design has been performed to find the significance of factors and interactive effects, as well as finite element model verification. Electrothermal and mechanical interactions are considered in the FEM. Experimental and numerical solutions have yielded similar results in terms of welding nugget properties. Asymmetry in electrical potential, temperature, stress distribution and geometry of shunted nugget is predicted and verified directly or indirectly. Intense effect of shunting current on nugget height, asymmetric growth of heat affected zone (HAZ) toward previous welding nugget, as well as concentration of alloying elements along grain boundaries are also discovered. Kim et al. [17]). Although most of these studies have included thermal, electrical and mechanical aspects of the RSW process, the asymmetry of shunting configuration due to existence of shunting (previous) nugget prohibits the use of 1D or 2D axisymmetric models.In this paper, shunting effect in RSW is investigated using FEM and the results are compared with experiments on AA2219. The influence of welding distance, current and time are investigated to consider shunting effect in final quality of the nugget. Experiments are designed inside the weldability range, while the results are compared to results of FEM after verification. have included thermal, electrical and mechanical aspects shunting configuration due to existence of shunting (prev 2D axisymmetric models. MethodsIn this paper, shunting effect in RSW is investigated using with experiments on AA2219. The influence of welding d investigated to consider shunting effect in final quality of inside the weldability range, while the results are compar

Numerical Study of Shunting Effect in Three-steel Sheets Resistance Spot Welding

“…An analytical model has been presented for the shunting effect in the RSW joint of AA2219 aluminu m alloy sheets with a thickness of 1 mm considering two consecutive spot welds [6]. Finally, the welding core diameter obtained from the presented analytical relationships by the finite element simulation results (validated with the experimental results [7]) was Figure 1. A schematic of the shunting phenomenon at a connection with more than one spot and diameter reduction of the welding core [4] compared and the results were well matched.…”

Influence of Shunting Current on the Metallurgical and Mechanical Behaviour of Resistance Spot-welded Joints in AA2219 Joints

“…The weldability window was obtained ( Fig. 4) after finding the allowable electrode force to provide an expulsion-free nugget diameter between 3.5 t s and 3.5 t s [20] and [23] where t s is sheet thickness [21].…”