Finite element analysis of residual stress of welding repair for gas pipeline

By the finite element analysis software ABAQUS and the function of coupling process between heat and stress, the methods of entirety welding repair and local welding repair were simulated for 20-steel gas pipeline, and the distributions of the two kinds of welding residual stress were obtained.At the same time, the stress of welding-repair joint was analyzed by ABAQUS under inner pressure and welding residual stress.The results indicate that the residual stress of the entirety welding repair is lower than that of the local welding repair.And under inner pressure and welding residual stress, the tensile stress of the entirety welding repair is lower than that of the local welding repair too.It shows that the entirety welding repair joint is stronger than the local welding repair joint.The method of the entirety welding repair can reduce the probability of stress corrosion cracking and fit for the engineering application.The research results provide theory base for optimizing welding repair technology.