钢-混凝土组合梁负弯矩区弹性畸变屈曲分析  

Elastic distortional buckling analysis of steel-concrete composite beams in negative moment region

作　　者：周旺保[1] 蒋丽忠[1,2] 邵光强[1] 余志武[1,2] 

机构地区：[1]中南大学土木建筑学院,湖南长沙410075 [2]高速铁路建造技术国家工程实验室,湖南长沙410075

出　　处：《中南大学学报（自然科学版）》2012年第6期2316-2323,共8页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金面上项目(资51078355);国家自然科学基金重点资助项目(50938008);国家"十二五"科技支撑计划项目(2011BAJ09B02)

摘　　要：基于畸变屈曲是钢-混凝土组合梁负弯矩区钢梁的重要屈曲模式,钢梁下翼缘提供给钢梁腹板的转动约束刚度及侧向约束刚度是影响其畸变屈曲性能的关键因素之一,对工字形钢-混凝土组合梁负弯矩区钢梁腹板提供给下翼缘的转动约束刚度及侧向约束刚度进行研究。采用利用能量法推导负弯矩区钢梁腹板对下翼缘的转动约束刚度及侧向约束刚度理论计算公式,并结合弹性介质中的中心受压薄壁杆件的屈曲理论推导钢梁侧向弯曲屈曲及侧向弯扭屈曲临界应力计算公式,进一步获得相应的屈曲弯矩。结合工程实例对转动约束刚度、侧向约束刚度及屈曲弯矩计算公式进行分析及讨论。研究结果表明:钢梁腹板转动约束刚度及侧向约束刚度均与外荷载呈线性关系,同时两者还可能出现负值;本文屈曲弯矩计算结果与ANSYS有限元计算结果较吻合;现有屈曲弯矩计算方法存在一定理论缺陷,且不同计算方法所得计算结果偏差较大;本文计算公式形式较简洁,适于工程应用。Based on the fact that distortional buckling is one of the important buckling modes for steel-concrete composite beams in the negative moment region,and the distortional buckling load depends significantly on the rotational restraint stiffness and lateral restraint stiffness provided by the lower cloud point flange to the steel beam web plate during buckling deformation,the rotational restraint stiffness and lateral restraint stiffness were presented.Based on the energy method,the analytical expressions for the rotational restraint stiffness and lateral restraint stiffness were derived,and combining the thin-walled bar buckling theory in elastic medium,the lateral bending buckling stress and lateral flexural-torsional buckling stress calculation and the corresponding critical moment formulas were derived.The results show that the rotational restraint stiffness and lateral restraint stiffness has linear relationship with external loads,both can be negative,the calculation results of this paper agree well with the ANSYS analysis results,and the deviation of the calculation results in existing computing methods that have some theory shortcomings is great.The analytical expressions is relatively more concise,and so it is suitable for engineering application.

关 键 词：钢-混凝土组合梁 畸变屈曲 转动约束刚度 侧向约束刚度 临界弯矩 负弯矩 

分 类 号：TU398.9[建筑科学—结构工程] TU312