Design of a laser welded thin metal tube structure incorporating welding distortion and residual stress

Abstract

The welding process, incorporating rapid heating and cooling, generates distortion and residual stress in the welded structures. In the design of a high quality welded structures, the weld distortion and residual stress have to be considered in advance. Especially, for the thin metal welded structures, the thermal distortion and residual stress have a severe effect on the structure’s precision, fatigue strength, buckling strength and so on. This study aims to analyze the design candidates of a laser welded thin metal tube structure in the view point of welding distortion and residual stress. Three design candidates were fabricated, and then the distortion was measured. And the residual stress distributions were calculated by using a commercial FEM package. The analysis results show that the distortion and residual stress were affected according to the position of weld line and the design of structure. By using the analyses the best one among the three design candidates was selected finally.