考虑真实火灾效应的钢管混凝土偏压构件耐火性能数值模拟

Numerical simulation of fire resistance of concrete-filled steel tubular eccentric compressive member considering real fire effects

采用FDS(fire dynamics simulator)对某一给定的小空间结构进行了火灾分析,通过Smokeview对FDS模拟的结果进行可视化,得到了三维动态的火灾发展过程,并提取了室内相对真实的升温曲线。在此基础上,通过热-力耦合的分析方法对考虑真实火灾效应时的钢管混凝土偏压构件的耐火性能进行了分析研究,并与标准火进行了比较。分析结果表明:采用ISO-834标准升温曲线计算得到的钢管混凝土柱的耐火极限比考虑真实火灾效应时得到的耐火极限小。此外,通过考虑真实火灾效应的不同参数作用下钢管混凝土偏压构件耐火极限的计算发现,长细比、火灾荷载比以及保护层厚度等对该类构件的耐火极限影响较为显著。

The fire resistance simulation of a given small FDS simulation results were visualized by Smokeview, to fire and and extract relative real temperature rising curve space structure was studied by using FDS software. The obtain a three-dimensional dynamic developing process of indeers. This paper presents a finite element（FE） model of concrete-filled steel tubular（CFST） columns to study the fire resistance of the columns under eccentric compressive loading and real fire effect,i, e. the analysis method considered the thermal-mechanical coupled effect. The re- sults show that the fire resistance limit of CFST columns calculated by ISO-834 standard fire curve is smaller than that calculated by the real fire curve. In addition, based on calculation of fire resistance limit of CFST members with different parameters under real fire effect, it is discovered that the slenderness ratio, fire load rate, thickness of pro- tective layer and so on have more significant effect on the fire resistant limit of this kind of member.