摘要
根据傅里叶热传导理论,提出蒸发阶段水分修正函数,建立改进温度场模型;结合非线性板壳理论和热弹塑性本构关系,建立了火灾下钢筋混凝土双向板的数值模型,发展现有计算程序,通过计算结果与试验结果对比,验证了模型及程序的可靠性。在此基础上,分析了火灾工况、约束作用、骨料类型、板厚和保护层厚度等参数对混凝土双向板变形行为和耐火极限的影响规律。结果表明:火灾工况、骨料类型、板厚和保护层厚度对双向板火灾行为影响较大;双向板变形行为和破坏模式对约束作用非常敏感,力学机理较为复杂。
Based on Fourier＇s heat transfer theory, the modified function of moisture over the temperature regions of water evaporation was proposed to establish the improved model of temperature field. According to the nonlinear shell theory and thermal elastic-plastic constitutive model, the numerical model and existing calculation program were developed to trace the behavior of two-way reinforced concrete slab in fire. The reliabilities of the numerical model and program were validated by test results. Furthermore, the model was used to investigate the effect of fire scenario, restraint, aggregate type, slab thickness and concrete cover on the deflection and fire resistance of two-way reinforced concrete slabs. The results from the parametric studies indicate that the fire scenario, aggregate type, slab thickness and concrete cover have significant effects on the fire resistance of RC slab. The deflection and failure mode are very sensitive to the restraint of the slab, and the mechanical mechanism is very complex.
出处
《工程力学》
EI
CSCD
北大核心
2015年第11期218-227,250,共11页
Engineering Mechanics
基金
国家青年自然科学基金项目(51408594)
中国博士后科学基金项目(2014M560461)
中央高校基本科研业务费专项资金项目(2014QNA78)
教育部高等学校博士学科点专项科研基金项目(20120095110027)
国家自然科学基金项目(51178143)
江苏高校优势学科建设工程项目
关键词
钢筋混凝土板
温度
火灾行为
数值分析
薄膜效应
reinforced concrete slab
temperature
fire behavior
numerical analysis
membrane effect
