钢管混凝土X形交叉柱轴压性能研究

为研究圆形和长圆形截面钢管混凝土柱交叉相贯形成的变截面不规则钢管混凝土组合柱,即钢管混凝土X形柱的轴压性能，采用有限元软件ABAQUS建立上述两种截面钢管混凝土X形柱的轴压模型，并通过与试验结果对比验证有限元模型的合理性，在此基础上，对圆形和长圆形截面钢管混凝土X形柱的受力全过程进行分析，并对钢管混凝土X形柱进行参数分析。研究表明，钢管混凝土X形柱在节点交叉区域钢管对混凝土产生不均匀的约束作用，混凝土中心区域受到的约束作用最大，其次是左右区域，钢管相交部位的混凝土受到约束最小，部分截面甚至在混凝土与钢管之间发生脱离。随着混凝土强度提高、钢材强度提高、钢管壁厚增加以及交叉角度加大，钢管混凝土X形柱的轴压承载力相应提高。

Compression behavior of the concrete-filled steel tubular X-column

To study the axial compressive behaviour of a novel composite column with irregular and variable cross-sections, namely concrete-filled steel tubular X-column (CFST X-column), which is consists of two inclined circular or long-circular concrete-filled steel tubular columns placed crosswise, ABAQUS finite element models of the CFST X-column are developed and verified by using the existing experimental results. The whole mechanical process of circular and long-circular CFST X-column under compression was analyzed, and a parametric analysis was conducted. Simulation results have shown that the concrete is unevenly confined by the steel tube in the cross area of the CFST X-column. The highest and lowest confinement effects are observed on the core area of the concrete section and steel tube crossing region, respectively. The confinement on the left and right areas are between the above two areas. Separation occurs between the steel tube and concrete on some sections. With the increase of the concrete and steel tube strength, the thickness of the steel tube, and the intersection angle, the axial compression capacity of the CFST X-column is enhanced.