钢箱梁横隔板-U肋交接处割焊残余应力分析

Analysis of Cutting and Welding Residual Stresses in Joints of Diaphragms and U-Ribs of Steel Box Girder

为研究钢箱梁正交异性桥面板横隔板与U肋交接处的残余应力分布规律,采用Abaqus有限元软件模拟横隔板的热切割和焊接过程,分析横隔板与U肋交接处热残余应力的分布特征,探讨切割速度和焊接速度对横隔板弧形切口处残余应力的影响。结果表明:横隔板弧形切口处产生切向残余拉应力,其值超过钢材屈服强度;焊接在横隔板与U肋焊接区局部范围引起沿焊缝方向的残余拉应力,且焊缝尾端的应力集中更为明显;弧形切口残余应力区宽度随切割速度的增加而减小,残余拉应力随焊接速度的增加而增大;选用较快的横隔板切割速度和较慢的焊接速度可减小弧形切口处残余应力分布宽度和应力值。

To study the distribution of residual stresses in the joints of diaphragms and U-ribs in orthotropic steel deck of steel box girder, the thermal cutting and welding processes of the diaphragms are simulated by using finite element software Abaqus. The distribution of thermal residual stresses in the joints of diaphragms and U-ribs are analyzed, and the effects of cutting and welding speed on the residual stresses in the arc notches of the diaphragm are also explored. The results show that residual tensile stresses in the tangential direction occur at the arc notches of the diaphragms, with values exceeding the yielding strength of the steel. Welding also locally induced residual tensile stresses along the welding joints in the welding zone of the diaphragms and U-ribs and the stress concentration in the ends of the welding joints is more distinct. The width of the residual stress zone in the arc notch decreases as the cutting speed increases, and the residual stresses increase as the welding speed increases. Thus, to choose a relatively fast cutting speed of the diaphragms and a slower welding speed can reduce the distribution width of the residual stresses at the arc notches as well as decrease the stress values.