圆锥形中空夹层钢管混凝土压弯构件抗震性能

选取合理的材料本构模型和混凝土损伤指标,通过ABAQUS软件建立圆锥形中空夹层钢管混凝土构件数值模型,并采用现有试验数据进行模型验证。在此基础上建立典型算例,分析典型算例的抗震性能指标,同时描述构件的破坏模态。对轴压比、空心率和长细比这3个对圆锥形中空夹层钢管混凝土抗震性能指标影响较为显著的参数进行分析,探究3个参数对滞回曲线极限承载力、延性系数和耗能能力的影响规律。比较圆锥形中空夹层钢管混凝土与不同截面尺寸的等截面圆中空夹层钢管混凝土抗震性能的差别,探究圆锥形中空夹层钢管混凝土与何种截面尺寸的圆中空夹层钢管混凝土可以实现抗震性能上的等效。结果表明:在一定范围内,轴压比和长细比的增大使得构件的耗能性能变差,空心率的增大使得构件的耗能性能变好,但需明确各参数的限值; 截面面积减小使得构件的承载力降低、耗能性能变差; 圆锥形中空夹层钢管混凝土的抗震性能与距其底部1/4高度处截面大小的圆中空夹层钢管混凝土等效。

Seismic Behavior of Tapered Concrete-filled Double Skin Steel Tube Compression-bending Members

The rational material constitutive model and concrete damage index were chosen, and the numerical analysis model of tapered concrete-filled double skin steel tubular(CFDST)specimens were established by the ABAQUS software. The results were compared with the existing experimental data to verify the rationality of the model. On the basis, a typical example was established, and the seismic performance index of the typical example was analyzed. At the same time, the failure mode of the component was described. The parameters that had significant influence on the seismic performance index of the tapered CFDST were analyzed, such as axial compression ratio, hollow ratio and slenderness ratio. The influences of three parameters on the ultimate bearing capacity, ductility coefficient and energy dissipation capacity of hysteretic curve were investigated. The seismic behaviors between tapered CFDST and uniform section CFDST with different section sizes were compared. The equivalent seismic performances of tapered CFDST and uniform section CFDST with different section sizes were explored. The results show that within a certain range, the increases of axial compression ratio and slenderness ratio make the energy dissipation performance of components worse, and the increase of hollow ratio makes the energy dissipation performance of components better, but it is necessary to define the limits of each parameter. The reduction of section area reduces the bearing capacity and energy dissipation performance of members. The seismic behaviors of the tapered CFDST are equivalent to the uniform section of CFDST at one quarter of the height from the bottom of the tapered CFDST.