Xie Xingkun, Shao Fei, Gao Lei, He Lixiang, Bai Linyue
College of Field Engineering, Army Engineering University of PLA, Nanjing 210007, China.
Materials (Basel). 2020 Jul 23;13(15):3282. doi: 10.3390/ma13153282.
BS700 high-strength steel is widely used in engineering. Welding residual stress during the manufacturing process has a significant influence on the structural safety and service life of steel structures. In this study, the residual stress of a BS700 butt-welded box section axial compression member was studied by the blind-hole method, its distribution law was summarized, and a residual stress distribution model was established. By establishing a finite element model considering initial geometric imperfection and residual stress, the influence of residual stress on the stability of axial compression members was analyzed. The results illustrated that the residual tensile stress near the weld in the welded box section axial compression members was the largest: the average residual tensile stress reached 76.6% of the measured steel yield strength, the residual tensile stress at the roof and web were almost the same, and the residual tensile stress at the corner was approximately 11.6% of the measured yield strength. The residual stress had a different influence on the stability factor of the axial compression members with different width-thickness ratios, and the influence decreased with the increase in the width-thickness ratio. In addition, when the slenderness ratio of members ranged between 20 and 70, the residual stress had a significant influence on the stability of members, while outside that interval, the influence was relatively small.
BS700高强度钢在工程中得到广泛应用。制造过程中的焊接残余应力对钢结构的结构安全和使用寿命有重大影响。本研究采用盲孔法对BS700对接焊接箱形截面轴心受压构件的残余应力进行了研究，总结了其分布规律，并建立了残余应力分布模型。通过建立考虑初始几何缺陷和残余应力的有限元模型，分析了残余应力对轴心受压构件稳定性的影响。结果表明，焊接箱形截面轴心受压构件焊缝附近的残余拉应力最大：平均残余拉应力达到实测钢材屈服强度的76.6%，顶板和腹板处的残余拉应力基本相同，角部的残余拉应力约为实测屈服强度的11.6%。残余应力对不同宽厚比的轴心受压构件的稳定系数有不同的影响，且随着宽厚比的增大，这种影响减小。此外，当构件的长细比在20至70之间时，残余应力对构件的稳定性有显著影响，而在此区间之外，影响相对较小。
