火灾下约束钢柱受力性能实用分析方法(Ⅰ)——轴力作用下的约束钢柱  

Practical analysis method for restrained steel columns in fire (Ⅰ)——restrained columns under axial compression load

作　　者：李国强[1,2] 王培军[1,3] Yong-Chang Wang 

机构地区：[1]同济大学土木工程学院,上海200092 [2]同济大学土木工程防灾国家重点实验室,上海200092 [3]山东大学,山东济南250061 [4]University of Manchester, PO Box88, Manchester, M60 1QD

出　　处：《土木工程学报》2010年第4期16-22,共7页China Civil Engineering Journal

基　　金：国家自然科学基金重点项目(50738005);国家自然科学基金创新群体项目(50621062)

摘　　要：给出了确定轴压约束钢柱在火灾升温条件下屈曲温度和破坏温度的简化计算方法,采用有限元方法、相关研究者的研究成果和试验结果对计算方法进行了验证。约束钢柱屈曲前,随着温度升高,轴力线性增加,截面弯矩很小并保持不变,采用无约束钢柱屈曲温度计算公式确定其屈曲温度,钢柱轴力考虑轴向约束的影响;约束钢柱屈曲后处于轴力和弯矩的共同作用下,利用截面屈服条件表示的轴力-弯矩相关关系确定其破坏温度,钢柱轴力取升温前初始轴力。本文方法计算结果与有限元分析结果和其他研究人员的研究成果吻合较好,与试验结果的比较表明本文方法偏于安全。A simplified method is developed for calculating the buckling temperature and failure temperature of restrained steel columns under axial load in fire. Results from the proposed calculation method are compared with those from finite element method simulation, Neves＇ s method and fire resistance tests. With the elevation of temperature, the axial force in the restrained column increases linearly and the bending moment remains small before buckling of the restrained column. The design equation for calculating the buckling temperature of unrestrained steel columns in fire is adopted for restrained steel columns by including the effect of axial restraint when calculating the axial force. After buckling, the restrained column is under the combined action of axial force and bending moment; the yield axial strength-plastic bending moment interaction curve of column section is adopted for calculating the failure temperature. The buckling temperature and failure temperature predicated by the simplified method agree well with those by ABAQUS and Neves＇ s method, and are on the safe side when compared with the test results.

关 键 词：约束钢柱 屈曲温度 破坏温度 数值分析 设计方法 

分 类 号：TU393.2[建筑科学—结构工程]