FEA Simulation Based Power Adaption for Laser Welding of Radii

Abstract

This paper describes an investigation on laser-MIG hybrid welding of sheet metals. Material of the sheets is an AlMg3Mn aluminum alloy, with a thickness of 3.5 mm. The 2-D T-joint structures investigated have convex radii of 20 mm to 50 mm. These radii lead to temperature elevations during welding and subsequently to failures in the weld seam. For a description of this phenomenon, the 2-D T-joint structures have been modelled in Abaqus FEA. Based on this FEA model and its resulting understanding of the temperature elevations, a weld power reduction method has been developed. The reduction of power has to correlate with the extent of the elevated temperature. A further conclusion is the necessary expansion of the adjustment beyond radius start and end point. For smaller radii, due to heat flow and its heat accumulation, a greater expansion is necessary.