圆钢管混凝土轴压短柱对比试验研究

摘要

为了综合比较各类圆钢管混凝土的轴压力学性能，共设计了4种截面形式的圆钢管混凝土短柱试件，包括圆实心钢管混凝土(圆实心)、内外钢管均为圆形的中空夹层钢管混凝土(圆套圆中空夹层)、外圆内方的中空夹层钢管混凝土(圆套方中空夹层)、内外钢管均为圆形的复式钢管混凝土(圆套圆复式)，对其轴压力学性能进行了对比试验研究。结果表明：复式钢管混凝土的力学性能最优，具有较高的承载力和轴压刚度；圆套方中空夹层钢管混凝土短柱的力学性能与实心钢管混凝土短柱接近，而圆套圆中空夹层钢管混凝土短柱的后期延性要稍差一些；实心钢管混凝土短柱和复式钢管混凝土短柱外钢管横向应变的发展要快于中空夹层钢管混凝土短柱；外钢管对中空夹层钢管混凝土短柱中夹层混凝土的约束作用要比对实心钢管混凝土短柱中的核心混凝土弱，内管截面形式对夹层混凝土所受约束效应程度的影响不大。最后，利用ABAQUS软件对4类圆钢管混凝土轴压短柱的轴力-应变曲线进行模拟，计算结果与试验结果接近。%In order to compare synthetically the mechanical behavior of 4 kinds of concrete-filled steel tubular columns under axial compression, a comparative experimental research was conducted. Four section forms were included, i. e. , concrete-filled steel tube ( CFST) with circular section, concrete-filled double-skin steel tube ( CFDST) with circular hollow section ( CHS) as both inner and outer tubes, CFDST with square hollow section ( SHS) as the inner tube and CHS as the outer tube, and composite concrete-filled steel tube ( CSCFST) with circular section. The research results show that the CSCFST has excellent mechanical properties, as well as high bearing capacity and axi-al stiffness. The mechanical behavior of CFDST ( SHS inner and CHS outer) is similar to that of CFST and the ductility of CFDST ( CHS inner and CHS outer) is slightly worse than that of CFST. The development of lateral strain of outer steel tubes of CFST and CSCFST columns is faster than that of CFDST columns. Compared with CFST column, the confinement of sandwiched concrete of CFDST columns provided by the outer steel tube is weaker, and the section type of inner tube has little effect on the confinement of sandwiched concrete. The axial load versus strain curves of 4 mem-bers subjected to axial compression were calculated by the finite element software ABAQUS, and the calculated results were close to the test results.