温升速率对某防火保护简支钢梁耐火时间的影响  

Effect of temperature rise rate on fire resistance period of a simple supported beam with fire coating

作　　者：李娟[1] 姚斌[1] 胡军[1] 

机构地区：[1]中国科学技术大学火灾科学国家重点实验室,安徽合肥230026

出　　处：《火灾科学》2010年第1期38-44,共7页Fire Safety Science

基　　金：国家自然科学基金项目资助(资助号50676089)

摘　　要：在钢结构抗火研究中通常基于标准温升曲线分析钢构件的火灾响应特性,采用更接近实际火灾场景的BFD自然温升曲线,运用有限元分析软件ANSYS研究了不同火灾温升速率对某防火保护简支钢梁耐火时间的影响,并与经验公式法进行比较。结果表明:有限元分析结果与经验公式法的计算结果基本一致;不同温升速率会导致钢梁温度场变化的差异性,进而影响钢梁的耐火时间;在快速温升时,荷载大小对钢梁耐火时间的影响较大;当荷载较大时,钢梁耐火温度降低,快速温升下钢梁耐火时间较短。The fire response characteristics of steel structure is usually studied based on the standard temperature rise curve. The BFD natural temperature rise curve which is closer to the real fire scenario is used in this paper. The effect of various tem- perature rise rate on fire resistance of a simply supported steel beam with fire coating was studied via the finite element analysis software ANSYS, and compared with the empirical formula method. The results indicate that finite element analysis are nearly the same with calculation of empirical formula; Different rates of temperature rise would result in different beam temperature distribution, which affecting the fire resistance period of the steel bearn; For the rapid temperature rise, the magnitude of load deeply affects fire resistance period of steel beam. Under higher load conditions, the limit temperature of steel beam is lower, and the fire resistance period is shorter with rapid temperature rise.

关 键 词：火灾温升速率 钢梁耐火时间 防火涂料 有限元分析 

分 类 号：TU892[建筑科学]