Numerical analysis for controlling residual stresses in welding design of dissimilar materials girth joints

Dissimilar metal girth welded joints have been widely used due to their efficient implementation and cost-effectiveness. It is of critical significance to understand the knowledge of residual stresses by numerical technology to determine precision requirements for manufacturing practice. A multi-layer welding process of a dissimilar welded joint is simulated in this literature by coupled thermalmechanical analysis. The welding simulation model is verified by previous experimental work. The magnitudes and distributions of residual stresses in a dissimilar girth pipe joint are predicted. This study describes the influence of welding sequences and the welding start/stop positions on residual stress profiles by the simulation model. Constraint conditions is considered to analyze residual stresses in such a dissimilar welded joint. The results demonstrate that residual stresses are asymmetrical in dissimilar pipe joints due to the difference in material properties. Residual stress profiles are considerably different since the effect of welding sequence and welding start/stop positions. The variations of residual stresses on both sides of the weld centerline are more complex than those in similar welded joints. Optimized welding sequence and appropriate constraint conditions are necessary to control welding residual stress and distortion of such dissimilar welded structures.