Effect of weld geometry on deformational behaviors of welded tubes in NC bending process

Different welding techniques may produce welds with different widths, profiles and properties. The weld and heat-affected zone (HAZ) of welded tube are regions of stress concentration where failures are likely to initiate, and the deformational behaviors of the weld joint are greatly affected by the geometry of the weld. Therefore, to investigate the contribution of weld geometry to deformational behaviors of the welded tube, 3D shell element models are established to simulate the welded tube NC bending process based on ABAQUS platform. The results show that: (1) Compared with the experimental results, 3D shell element model can demonstrate the forming features well. (2) As the weld line locates on the outside, it can be seen that the tangent strain and thickness strain measured in weld joint and neighbouring parent with a narrow weld are slightly higher than that with a wider weld zone. The weld width has little effect on the wall thickening of the welded tube. (3) With larger weld width, the cross-sectional deformation of welded tube becomes more severe.