Application of point fixing welding in finite element modeling of large structural pipeline steel assembly welding

For the butt welding of large structural pipeline steel components, finite element model is conducted on different equivalent models of X60 point fixing welding of pipeline steel. It obtains the results of welding deformation and residual stress, and verifies the simulation results. The results indicate that different equivalent models of point fixing welding result in the same trend of welding deformation and residual stress, proving the accuracy of the finite element model. The peak values of welding deformation are all near the weld position, and the equivalent spring connection obtained by point fixing welding has the smallest welding deformation error, with a maximum error value of 2.10%. Different equivalent schemes of point fixing welding have little effect on the peak value. The residual stress error obtained by equivalent spring connection of point fixing welding is the smallest, with a maximum error of 4.18%. Therefore, the equivalent spring connection of point fixation welding is more suitable for finite element model of large pipeline steel group butt welding, and has practical guiding significance for predicting welding deformation and residual stress in engineering applications.