防屈曲支撑理论分析与有限元模拟  

Theoretical and Finite Element Analysis of Buckling-Restrained Braces

作　　者：王华琪[1] 丁洁民[1] 姚兴华 

机构地区：[1]同济大学建筑工程系,上海200092 [2]黑龙江省火电第三工程公司,黑龙江哈尔滨150041

出　　处：《沈阳建筑大学学报（自然科学版）》2008年第2期191-195,共5页Journal of Shenyang Jianzhu University：Natural Science

基　　金：上海市高层建筑钢结构设计规程(20000391)

摘　　要：目的研究保证防屈曲支撑稳定工作性能的问题,给出防屈曲支撑的构成要求.方法对防屈曲支撑进行理论分析,并结合通用有限元程序,进行二次开发,对六种不用类型的防屈曲支撑的有限元模型进行分析.结果防屈曲支撑的整体稳定的理想条件为屈曲约束比ζ大于1,通过有限元模拟分析初始缺陷对支撑稳定工作的影响,提出屈曲约束比ζ的限值应提高.屈曲约束单元内填充的砂浆或混凝土能有效防止支撑的高阶屈曲.支撑的扭转屈曲可通过控制连接段的宽厚比不超过Ei/2(1+υ)fy来防止.结论通过理论分析给出保证防屈曲支撑稳定工作的条件,修正屈曲约束比要求以考虑初始缺陷的影响.分析中不同截面类型的支撑对屈曲约束比的不同要求是由截面尺寸不连续引起,因此对不用的支撑类型均可采用相同的屈曲约束比要求.The buckling-restrained braces are analyzed to study the problems of how to ensure stable performance of buckling-restrained braces. Then the structural requirements are obtained. Theoretical analysis of buckling-restrained braces was presented. On the basis of finite element program, secondary development was proceeded to analyze the finite element model of six different buckling-restrained braces. The ideal requirement to prevent the brace＇s resistance to overturning was that the buckling-restrained ration should be more than one. By finite element analysis, the buckling-restrained ration limited value should be increased considering the initial flaw＇ s effects on buckling-restrained braces. The mortar or concrete filled in the outer tube could resist the brace from higher-mode buckling, and the brace＇ s twist buckling could be prevented by limiting the flakiness ratio of linkage section in √Ei/2（1＋v）fy. Thus, the analysis results of resistance to overturning, higher-mode and twist buckling are obtained in this paper. The buckling-restrained ratio should be modified according to the initial flaw＇s effects on buckling-restrained braces. The different required values of buckling-restrained ratio of buckling-restrained braces are because of discontinuous section size, so different types of buckling-restrained braces can adopt the same value of buckling-restrained ration.

关 键 词：防屈曲支撑 有限元 屈曲约束比 间隙 

分 类 号：TU352.1[建筑科学—结构工程]