Q460高强钢焊接箱形截面轴压构件整体稳定性能研究

为研究高强度钢材轴心受压钢柱的整体稳定性能，对5个国产Q460钢材焊接箱形截面柱进行了轴心受压试验研究。试验对试件的几何初弯曲、荷载初偏心以及截面的纵向残余应力分布均进行了测量。基于试验结果，分析了该类钢柱的失稳破坏形态和整体稳定承载力，建立了有限元分析模型并对试验结果进行模拟计算。研究结果表明：试件破坏模态均为整体弯曲失稳形态，大部分试件稳定承载力高于规范设计值；有限元分析模型能够准确地考虑几何初始缺陷和残余应力的影响，计算结果与试验结果吻合良好；通过与国内外钢结构设计规范的对比，提出了国产Q460高强钢焊接箱形截面轴压构件整体稳定设计的建议方法，即可以统一采用我国或欧洲规范的b类曲线进行设计，而不需要按板件宽厚比大小进行分类。

Overall buckling behavior of Q460 high strength steel welded box section columns under axial compression

In order to investigate the overall buckling behavior of Q460 high strength steel columns under axial compression, 5 full-scale specimens were tested and the initial bending, loading eccentricity and sectional residual stress were also measured. Based on the experimental results, the failure mode and buckling capacity were clarified, and a finite element model was established to simulate the overall buckling behavior of such columns. It is found that the finite element model can well describe the effects caused by both initial geometric imperfections and residual stresses, and the calculated results through finite element analysis have a good agreement with experimental results. The validated model was further implemented for a large number of parametric analysis, and the calculated results were compared with different steel structure design codes. The design method for the overall buckling behavior of Q460 high strength steel welded box section columns was suggested, i.e. the column curve b in both GB 50017-2003 and Eurocode 3 can be employed to design such structural members.