升降温条件对约束钢梁抗火性能的影响  

Effect of temperature rise and drop on constraining the fire resistance of steel beam

作　　者：刘东亚[1] 杨秀萍[1] 

机构地区：[1]天津理工大学机械工程学院,天津300384

出　　处：《天津理工大学学报》2010年第5期11-15,共5页Journal of Tianjin University of Technology

基　　金：火灾科学国家重点实验室资助项目(HZ2005-KF05);天津市高等学校科技发展基金资助项目(20040505)

摘　　要：采用有限元方法对约束钢梁的火灾性能进行模拟,并与试验结果进行比较,在验证仿真模型正确的基础上,研究不同升降温条件下钢梁的火灾响应,分析各参数对钢梁抗火性能的影响。结果表明:升温最高温度Tmax和形状系数Sc越大,升温速率越大,梁的耐火时间越短,变形越大;到达最高温度所用时间Tmax越大,升温越慢,且受火时间越长,变形越大,但相应的耐火时间也增长。短热模型较长冷模型耐火时间长,变形小,对抗火有利。降温段约束梁的挠度均有恢复,但升温时变形越大,降温后的残余变形也越大.Finite element method is used to simulate fire behavior of steel structure,the results acquired from experiment are compared with those from numerical simulation,based on the correct simulation model,the fire response of stell beam under different temperature rise and drop have been studyed,and the parameters on fire resistance of stell beam have been analyzed.The results indicate that the highest temperature of fire（Tmax）and the shape constant（Sc）are larger,which means temprature rise rate is higher,fire-resistant duration of steel beam is shorter,structure distortion of steel beam is larger;the time spent on reaching the highest temperature（Tmax）is longer,temprature rise rate is lower,and the fire time is longer,structure distortion of steel beam is larger,but fire-resistant duration of steel beam is larger.Compared to long cold model,fire-resistant duration of short heat model is longer,and structure distortion is smaller,which is benefit to fire resistance.When temperature descends,the distortion of stell beam is reduced,but the distortion when temperature rising is larger,residual deformation after temperature descend is larger.

关 键 词：升降温条件 有限元法 钢梁 火灾性能 

分 类 号：TU391[建筑科学—结构工程] TU311.41