高温后中空夹层钢管混凝土柱轴压性能研究

Analysis of concrete filled double skin steel tubular columns subjected to axial compression performance after high temperature

为了分析高温后中空夹层钢管混凝土(简称CFDST)构件轴心受压力学性能,在试验验证的基础上,采用数值模拟的方法对高温后的轴压工作机理进行剖析,探讨温度、空心率、名义含钢率、内外钢管屈服强度及混凝土抗压强度对CFDST力学性能的影响。研究结果表明:随着构件曾经历温度的升高,极限承载力呈下降趋势;外钢管屈服强度对CFDST构件极限承载力的提高有显著影响,混凝土强度对提高常温阶段构件的极限承载力影响较大,但随着温度的升高,影响逐渐降低,空心率、内钢管的屈服强度对高温后CFDST构件极限承载力影响很小。

In order to analyze the axial compression mechanical properties of concrete filled double skin steel tu-bular (CFDST)members after high temperature,the numerical simulation method was adopted to interpret the working mechanism under axial compression after high temperature based on the test results,and the influence of relevant parameters,such as temperature,hollow rate,the nominal steel ratio,yield strength of internal and ex-ternal steel tube,the strength of concrete,on the mechanical properties of CFDST was discussed.The results in-dicate that the ultimate bearing capacity decreases with the increase of temperature that the member experienced;Yield strength of outer steel tube has remarkable effect on ultimate bearing capacity of CFDST.The strength of concrete has great effect on improvement of the ultimate bearing capacity at normal temperature,but with the rise of temperature,the influence gradually decreases.However,hollow rate,yield strength of the inner steel tube has little impact on ultimate bearing capacity of CFDST components after high temperature.