钢管混凝土轴压短柱性能三参数分析与计算

在深入研究套箍系数对钢管混凝土轴压短柱力学性能的影响中,发现并用试验证明了仅用套箍系数这一综合参数不能全面衡量和反映参数变化对钢管混凝土破坏模式、承载力、延性等力学性能的影响;基于试验研究和参数分析,确定了利用套箍系数衡量钢管混凝土力学性能的合理适用范围;提出了用钢管混凝土3个基本参数(试件含钢率、混凝土强度和钢材屈服强度)来衡量和反映钢管混凝土力学性能的方法;并通过回归分析给出了基于这3个基本参数的钢管混凝土轴压短柱轴向力-纵向应变关系曲线,复杂应力场中钢材纵向(横向)应力-纵向应变关系曲线、核心混凝土纵向应力-纵向应变关系曲线和紧箍力-纵向应变关系曲线的简化计算公式,简化计算曲线与试验曲线吻合良好.

Analysis and simplified calculation of mechanical behavior of concrete-filled steel short columns under axial compression based on three parameters

This paper presented a detailed investigation about the influence of confining factor on concrete-filled steel tubes(CFT).Both experimental investigations and theoretical analysis proved that the confining factor was not the only parameter to represent failure modes,ultimate bearing capacities and ductility of CFT.Based on the experimental research and parameter analysis,a reasonable range was given where confining factors acted as the representative parameters.A suggestion was made which used three parameters(Concrete strength,yielding stress of steel and steel ratio) to represent the behaviors of CFT.Then the paper regressed simplified formulae to calculate the axial force vs.longitudinal strain curves of CFT,longitudinal or transverse stress vs.longitudinal strain curves of steel in polyaxial stresses,longitudinal stress vs.longitudinal strain curves and confining force vs.longitudinal stain of the core concrete.The simplified formulae correlated well with the experimental results.