Investigations of heat source models in transient thermal simulation of pulsed MIG welding of AA6061-T6 thin sheet

Abstract

Abstract The automobile and aviation industries are exhaustively working on weight reduction by replacing steel with aluminium alloy. However, joining the aluminium alloy body panel is remain a big challenge because of the inherent properties of aluminium. The dynamic behaviour of arc plasma in the pulsed MIG welding process is a multifaceted heat mass transfer phenomenon involving chemical, electro-magnetic, and fluid dynamics. Numerical simulation using FEA techniques are greatly helpful in understanding responses of weld bead and material behaviour. Simultaneously it reduces time and cost consuming experimental trial and error approach. The approximation of the welding arc heat source is paramount for precise prediction in the welding process simulation model. The article focuses on the comparison, suitability and effects of various moving heat source models by developing the transient thermal simulation of pulsed MIG welding of 1mm thick AA6061-T6 sheet in ANSYS workbench. Moving heat source models were developed as ANSYS APDL command subroutine. It is observed that for 1mm thin sheets Gaussian surface heat source model is also valid. The difference in temperature field is not prominent in comparison with Goldak’s double ellipsoidal heat source model.