Abstract:To study the distribution characteristics and influencing factors of longitudinal welding residual stresses in high strength Urib stiffened steel plates of Q420 grade, the model test of longitudinal residual stresses in Urib stiffened steel plates were measured using the method of sectioning technique. Besides, a 3D solid thermal elastic plastic finite element method (FEM) was developed by using an element birth and death method to simulate the process of weld filler variation and welding, and the residual stress distribution between high strength steel and common strength steel was analyzed. Furthermore, the effects of flange thickness, Urib thickness, space, width and height on welding residual stresses were studied comparatively. The results show that the welding sequence in bilateral rib has no effect on stress distribution. The longitudinal compressive residual stresses out of weld zone is irrelevant to yield strength. Plate thickness, Urib width and height are the main factors affecting welding residual stresses in high strength Urib stiffened steel plates.