方钢管混凝土组合柱抗火性能分析

FIRE RESISTANCE ANALYSIS OF CONCRETE-FILLED SQUARE STEEL TUBULAR COLUMNS

利用ABAQUS有限元软件,采用顺序热力耦合分析方法,建立方钢管混凝土组合柱耐火性能的有限元分析模型,并通过试验验证模型的可靠性。在此基础上,对影响方钢管混凝土组合柱耐火极限的主要因素进行深入分析。结果表明:混凝土的截面面积、荷载比、长细比及防火保护层厚度是影响组合柱高温下受力性能的重要因素。在有效的防火保护下,组合柱能承担更大的轴向力,比圆截面、方截面柱更具优势;荷载比越大,组合柱耐火极限越低,轴压比小于0.5时影响更为显著。

The finite element analysis model of concrete-filled square steel tubular(CFST)composite columns was established by using the sequential thermo-mechanical coupling analysis method and ABAQUS finite element software,and its reliability was verified by tests.On this basis,the factors affecting the fire resistance of concrete-filled square steel tubular columns were deeply analyzed.The results showed that the section area,load ratio,slenderness ratio and the thickness of fire protection layer of concrete were important factors affecting the mechanical properties of composite columns at high temperature.Under the effective fire protection,the composite column could bear greater axial force than the circular section and square section columns,the greater the load ratio,the lower the fire resistance limit of the composite column,the more significant the effect was when axial compression ratio n<0.5.