Welding residual stress of K-joint and its influence on stress concentration factor

Using the finite element software ANSYS, taking K-joints as the study object, numerial simulation was performed for the welding process and the annealing process using the birth-death element technology. The welding residual stress of the managed node was studied and the distributions of welding temperature field and stress field were obtained. The axial loads were applied on two different K-joint models, one with welding residual stress and the other without welding residual stress while just considering the influence of welding seam on the K-joint. The stress concentration factors of these two models were calculated and the influence of the welding residual stress on stress concentration factor was obtained. The results show that the welding residual stress is reduced significantly using annealing process, the risk of deformation and fracture failure is reduced, and the safety performance of the managed node is greatly improved. The structure stress state is very complex, and the hot spot location and the hot spot stress concentration factor are related to size parameters, load type, loading mode, the welding seam structure.