全焊接钢结构桥梁焊接变形和残余应力的预测与控制研究

On Prediction & Control Study of Welding Deformation & Residual Stress of Overall Welded Steel Structure Bridge

以上海闵浦二桥中的典型整体焊接节点为背景,利用热弹塑性有限元法对节点的焊接残余应力进行预测。研究结果显示:合理的多层焊方案,通过焊接变形和残余应力的相互抵消,可以起到减少焊接变形和残余应力的作用;得到了上、下弦节点(I型)的残余应力分布;实现了上下弦节点(I型)加工局部以及整体模型的焊接变形预测;为焊接变形的控制、焊接工艺的优化以及最佳装配焊接工艺的制订提供理论依据。

With the background of typical overall welding nodes in Shanghai No.2 Minpu Bridge,the welding residual stress of nodes by using thermal elastic-plastic finite element methods is predicted in this paper.The research results can show that 1) the reasonable multi-layer welded solutions can decrease the effects of welding deformation and residual stress for the case of offsetting the welding deformation and residual stress;2) the residual stress distributions of top & bottom chord nodes(type I) are obtained;3) the deformation forecast of top & bottom chord nodes(type I) partial processing and overall model is realized;4) the theory basis for welding deformation control,welding processing optimization and establishment of best assemble welding technology is provided.