为研究圆端形钢管混凝土(CFRT)轴压短柱的力学性能,对4个圆钢管混凝土(CFT)轴压短柱和10个圆端形钢管混凝土轴压短柱进行试验研究,探讨了不同宽厚比和钢管厚度对其极限承载力的影响,应用ABAQUS有限元软件进行三维实体单元建模,对圆端形钢管混凝土轴压短柱进行非线性有限元分析;基于ABAQUs参数分析,考虑宽厚比对套箍作用系数的影响,建立了圆端形钢管混凝土轴压短柱极限承载力实用计算公式。结果表明:在其他条件相同的情况下,圆端形钢管混凝土轴压短柱的极限承载力随钢管壁厚及圆端形宽的增大而增大;随着圆端形宽厚比的增加,圆端形钢管混凝土轴压短柱的约束效应减弱,核心混凝土轴向应力的提高程度减缓;计算结果与试验结果较为吻合。
In order to understand the mechanical behaviors of concrete-filled round-ended steel tubular (CFRT) stub columns, an experimental study on 4 concrete-filled circular steel tubular (CFT) stub columns and 10 CFRT stub columns under concentric loading in compression to failure was conducted. The influences of ultimate bearing capacity of the stub columns under different flakiness ratios and wall-thicknesses of steel tube were explored. ABAQUS was used to establish the 3D finite element model and to analyze the behaviors of the stub columns under axial compression. Based on ABAQUS simulation analysis and with the influence of flakiness ratio on confinement coefficient considered, a practical calculation formula for the bearing capacity of CFRT stub columns was proposed. The results show that when other parameters are the same, with the increase of wall-thickness and width of the section of CFRT stub columns, the ultimate bearing capacity of CFRT stub columns under axially loading are enhanced; the confinement effect of the stub columns decreases with the increase of flakiness ratio and the increase degree of axial stress in core concrete is reduced. The results with the formula are in good agreement with the experimental results.