焊接顺序对薄壁箱梁变形和残余应力的影响

Influence of Welding Sequence on Welding Residual Stress and Deformation of Thin-walled Box Girder

为了优化起重机用Q345材料薄壁箱梁结构的焊接顺序,采用有限元热弹塑性分析方法对不同焊接顺序的焊接变形和残余应力进行了数值模拟。定量描述了焊接顺序对焊接变形和残余应力的影响。通过对比分析,总结了焊接变形和残余应力的变化规律,提出了薄壁箱梁结构的最优焊接顺序。结果表明,采用同时同方向分段退焊的焊接顺序,并按照图5中方案三或四进行施焊,可有效控制薄壁箱梁结构的焊接变形和残余应力。

To optimize the welding sequence on structure for thin-walled box girder of material Q345 used for crane, the welding residual stress and deformation was simulated by finite thermo elastic-plastic method on the basis of different welding sequences. The simulation quantitatively describes the influence of welding sequence on the welding residual stress and deformation. The law of welding residual stress and deformation was concluded by comparison and analysis, and the optimal welding sequence on the structure for thin-walled box girder was proposed. The results show that it can effectively control the welding residual stress and deformation on the structure for thin-walled box girder if the welding sequence is adopted as backstep welding simultaneously and in the same welding direction, according to the scheme three or four in figure 5.