Longitudinal bending deformation, often induced during gas metal arc welding of long pipe structures, plays a negative role in the accuracy of assembly, external appearance, and various strengths of welded pipe components. In this paper, an experimental and numerical study of pipe welding distortion is presented. A 3D thermo-elastic-plastic finite element model for multi-seam welds (composed of longitudinal (L-seam) and circumferential (C-seam) welds) of pipe components was developed to predict longitudinal bending deformation. The finite element method and experimental results demonstrate good agreement. Therefore, the proposed model can accurately predict welding distortions in multiseam welded pipe structures. Moreover, the results reveal clear distinctions between the longitudinal bending deformations induced by L-seam and C-seam welds due to different selfrestraint strengths. Finally, another characteristic, the bending angle, is analyzed. Linear and nonlinear relationships are observed between the sine of the bending angle and weld length for L-seam and C-seam welds, respectively.

纵向弯曲变形通常是在长管结构的气体金属电弧焊过程中引起的，它对组装的准确性，外观以及所焊接的管道部件的各种强度起负面作用。本文对管道焊接变形进行了实验和数值研究。建立了用于管件的多缝焊接（由纵向（L形）缝和圆周（C形）缝组成）的3D热弹塑性有限元模型，以预测纵向弯曲变形。有限元方法与实验结果吻合良好。因此，所提出的模型可以准确地预测多缝焊接管结构中的焊接变形。此外，结果表明，由于不同的自约束强度，L型缝和C型缝的纵向弯曲变形之间存在明显的区别。最后，分析了另一个特性，即弯曲角度。对于L型缝和C型缝，分别在弯曲角度的正弦和焊缝长度之间观察到线性和非线性关系。