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采用ABAQUS有限元软件对型钢-方钢管混凝土轴压短柱的荷载-变形曲线进行了有限元分析,探讨了型钢-方钢管混凝土轴压短柱、等截面普通方钢管混凝土轴压短柱、等截面且等体积含钢率的型钢-圆钢管混凝土轴压短柱的内力变化情况。分析结果表明:三种短柱中型钢-圆钢管混凝土轴压短柱的极限承载力最大且延性最好;与等截面普通方钢管混凝土轴压短柱相比,型钢-方钢管混凝土轴压短柱中核心混凝土纵向应力有所增长,钢管屈服后纵向应力降低速率、环向应力增加速率减缓,钢管对核心混凝土的约束作用减小;与等截面且等体积含钢率的型钢-圆钢管混凝土轴压短柱相比,型钢-方钢管混凝土轴压短柱角部端点的约束效果最明显,钢管中点的约束效果最弱,型钢-圆钢管对核心混凝土的整体约束最强,型钢屈服后纵向应力略低于其屈服强度,且型钢的翼缘部分抗压强度比腹板部分的抗压强度高;等型钢含量情况下,随着翼缘长度b与腹板高度h比值的增大,轴压短柱的极限承载力越来越低,当b/h=0,即十字形钢骨-方钢管混凝土轴压短柱承载力最高;等体积含钢率下,普通方钢管混凝土柱轴压短柱承载力最低,随着型钢截面面积As与方钢管截面面积At的比值的增大,轴压短柱的极限承载力先增后降,当As/At≈0.8时,承载力达到最大值。
The finite element analysis of load-deformation curve of CFST column under axial load was carried out by using ABAQUS finite element software. The effects of concrete-filled square steel tubular short columns and constant-section CFST columns under constant axial load were discussed. Sectional and Equal Volume Steel Ratio of Steel-Concrete Filled Steel Tube Short Columns Internal Force Change. The analysis results show that the ultimate bearing capacity of the three kinds of short columns with CFRP-CFST columns is the highest and the ductility is the best. Compared with the common square CFST columns, the axial compression of the CFST-CFST columns The longitudinal stress of the core concrete in the column increased, the longitudinal stress reduction rate of the steel tube after yielding, the rate of increase of the hoop stress slowed down, and the confinement effect of the steel tube to the core concrete was reduced. Compared with the section steel tube with the same cross section and the same steel content ratio Compared with the axial compression short columns, the constraint effect of the end of the short steel columns of CFST-CFST column is the most obvious, and the restraint effect of the mid-point of the steel pipe is the weakest. The overall constraint of the SRC- The longitudinal stress is slightly lower than the yield strength, and the compressive strength of the flange part of the section steel is higher than the compressive strength of the web part. With the increase of the ratio of the flange length b to the web height h, When b / h = 0, the bearing capacity of the cross-section steel-concrete short column with square steel tube is the highest; under the same steel content, the common square concrete filled steel tubular column shaft Short column bearing capacity of the lowest , The ultimate bearing capacity of the axially compressed short column first increases and then decreases with the increase of the ratio of the sectional area As of the section steel to the cross-sectional area At of the square steel. When As / At≈0.8, the bearing capacity reaches the maximum value.