摘要
在钢管混凝土构件中内置型钢可有效提高整个构件的承载力和耐火性能。采用ABAQUS软件建立了标准火灾下内配型钢的圆钢管混凝土轴压构件的热力耦合数值模型,并与已有研究者完成的试验数据进行了对比验证;在此基础上,计算了火灾作用下该类构件柱顶轴向位移和跨中挠度随升温时间变化的关系曲线,根据破坏特征可以分为升温初期膨胀阶段、轴向压缩阶段和破坏阶段,并确定了该类构件的耐火极限;最后计算了火灾作用下每个组件间的相互作用力和参数分析。结果表明:随着温度的升高,钢管与混凝土、混凝土与型钢之间的接触应力呈降低趋势;火灾荷载比、长细比、钢管含钢率及防火保护层厚度对构件耐火极限影响较为显著。
The incased profiled steel can effectively improve the bear-capacity and fire performance of the concretefilled steel tubular( CFST) members. This paper presents a thermodynamic coupling finite element( FE) model of concrete-filled steel tubular( CFST) column with encased profiled steel to study the fire performance under axial compression using the ABAQUS software. The numerical results of steel reinforce concrete( SRC) and CFST members match well with the other researchers' experimental results. Based on the FE model,the relationships of axial displacement to time and mid-span deflection to time of the mombers were calculated when they expose to fire. The whole fire stage includes three phases according to the failure modes,such as initial expending stage,compression stage and failure stage. The fire resistance limit of the CFST columns with encased profiled steel was calculated for ISO834 standard fire. Finally the interaction forces between the components were calculated and the paramenter analyses were carried out. The results show that the contact stresses between steel column and concrete and between concret and profile steel decrease with increase of temperature. The fire load ratio,slenderness ratio of column,the steel rate of tube and thickness of fire protection layer have more significant effects on the fire resistance limit.
出处
《自然灾害学报》
CSCD
北大核心
2015年第2期52-59,共8页
Journal of Natural Disasters
基金
国家自然科学基金项目(51468037)
甘肃省高等学校科研项目(2013A-032)
关键词
内配型钢的圆钢管混凝土
轴压构件
耐火性能
接触应力
参数分析
concrete-filled steel tubular(CFST) column with encased profile steel
axial compression component
fire resistance
contact stress
parametric analysis
