Numerical simulation of welding residual stress of tube-to-tubesheet joint in heat exchangers

Using finite element program-ABAQUS, the welding residual stress of tube-to-tubesheet joint in heat exchangers had been numerically simulated. The distribution of welding residual stress was obtained. A comparison between tube end extended out of tubesheet welded joint and inside hole welded joint was made. The welding residual stress of inside hole welded joint is much smaller than that of tube end extended out of tube sheet joint. So using inside hole welded joint can decrease the susceptibility of stress corrosion cracking (SCC). The maximum of radial stress exists in the HAZ outside surface of tubesheet, which has great influence on tubesheet surface cracks. The maximum of hoop stress appears in the weld root, which has great influence on the connection failure between tube and tubesheet. The residual stress of former pipe bead is decreased due to the later pipe welding heating, which is useful for decreasing the susceptibility of SCC. This work provides a theory reference for optimizing the welding procedure and controling the welding residual stress for tube-to-tubesheet joint.