火灾下轴压钢柱破坏的判断准则分析  

Failure Criteria of Axially Loaded Steel Columns at Elevated Temperature

作　　者：王玲玲[1] 李国强[2] 

机构地区：[1]华侨大学土木工程学院,福建厦门361021 [2]同济大学土木工程学院,上海200092

出　　处：《防灾减灾工程学报》2013年第6期637-643,650,共8页Journal of Disaster Prevention and Mitigation Engineering

基　　金：华侨大学科研基金项目(11HZR12);国家自然科学基金项目(50728805)资助

摘　　要：介绍了火灾下轴压钢柱的破坏准则。利用数值分析的方法,根据不同的破坏准则计算火灾下轴压钢柱的临界温度。火灾下钢材的力学性能分别参照EC3和CECS选取。通过对临界温度计算结果的对比分析,发现:①2个变形准则给出的结果基本相同,但以变形准则为判断依据往往会高估构件的临界温度;②应用变形准则需具备一定条件,即火灾下构件的破坏形式为整体失稳或截面强度破坏,若构件发生局部屈曲,变形准则不适用;③同一破坏准则下,火灾下钢材性能分别按照EC3和CECS选取,临界温度计算结果相差超过200°C。最后,给出临界温度设计曲线的上、下限,以方便工程应用。Failure criteria of axially loaded steel columns under fire are introduced in this paper. Critical temperatures of steel columns are analyzed numerically according to different failure crite- ria. Mechanical properties of steel at elevated temperature are calculated by EC3 and CECS, re- spectively. Comparisons are made among different predicted results according to different failure criteria. The study shows that： （1） two deformation criteria give generally the same results, both overestimate critical temperatures; （2） it is worth to be noticed that the deformation criteria are only applicable under the condition that the global failure occurs;（3） mechanical properties of steel at elevated temperatures have significant influence on critical temperature of axially loaded columns, more than 200 ℃ differences are observed between temperatures predicted by EC3 and CECS. The upper and lower limits of critical temperatures for axially loaded steel columns are provided for convenient use.

关 键 词：火灾 轴压钢柱 破坏准则 防火保护设计 临界温度 耐火极限 

分 类 号：TU391[建筑科学—结构工程]