火灾后方中空钢管混凝土柱滞回性能有限元分析

为研究火灾后方中空夹层钢管混凝土柱的滞回性能，采用合理的本构关系，建立有限元模型，分析参数有受火时间、轴压比、混凝土强度、空心率，并与相应试验结果进行比较，承载能力、滞回曲线以及破坏模态吻合较好。同时对火灾后方中空夹层钢管混凝土柱滞回性能进行机理分析，结果表明：混凝土强度对滞回曲线影响不明显，分析滞回骨架曲线得知承载力随着构件受火时间增加、轴压比的增大，空心率减小而减小。随着受火时间的增加，空心率的增大，构件的滞回耗能能力更好。

FEA of hysteretic behavior of concrete filled double-skin steel tubular column after exposed to fire

In order to study the hysteretic behavior of concrete filled double skin steel tubular exposed to fire，this paper choose a reasonable constitutive model and established a reasonable finite model．Axial load ratio, time exposed to fire, strength of concrete and void ratio are the parameters of this analysis. The numerical results are verified, and the bearing capacity, hysteretic loops, and failure modes are consistent with other researchers’ experimental results. The working mechanism of hysteretic behavior of concrete filled double skin steel was investigated. The results show that: strength of concrete have little effect on hysteretic loops. But the time exposed to fire and axial load ratio affect hysteretic loops significantly. The result by analyzing hysteretic loops show that the bearing capacity decrease with the time exposed to fire increase, void ratio decrease and axial load ratioincrease, and axial deformation get better with void ratio increase.