Finite Element Method Analysis on Welding Residual Stresses of Large Electromotor Rotor

Using axisymmetric finite elements model,this study aims to investigate the distributions of the welding residual stresses in a large scale electromotor rotor and the effects of welding procedures, such as welding simultaneously at both sides; shrinkage fitting, preheating,welding sequence for multipass welds,etc.The results indicate that high tension stresses in three directions were found in weld bead and its surrounding area; welding simultaneously at both sides can reduce the radial residual stress; heat fitting can reduce the residual stresses in three directions; preheating can reduce the tangential residual stress; the radial residual stress in multipass welds was determined mainly by the last layer, especially the last bead; welding the last beads, of both sides simultaneously can reduce the radial residual stress,while it's not important whether the foregoing beads are welded simultaneously.These results are attractive for the knowledge and the control of the welding residual stresses in the large electromotor rotor.