多层中心支撑钢框架结构抗震性能简化评估方法  

A simplified method for seismic performance evaluation of MDOF steel concentrically braced frames

作　　者：董志骞 李钢[1] 李宏男[1,2] DONG Zhiqian;LI Gang;LI Hongnan(State Key Laboratory of Costal and Offshore Engineering, Dalian University of Technology, Dalian 116024, China;College of Civil Engineering, Shenyang Jianzhu University, Shenyang 110168, China)

机构地区：[1]大连理工大学海岸和近海工程国家重点实验室,辽宁大连116024 [2]沈阳建筑大学土木工程学院,辽宁沈阳110168

出　　处：《建筑结构学报》2018年第5期1-9,共9页Journal of Building Structures

基　　金：国家自然科学基金优秀青年科学基金项目(51422802);中央高校基本科研业务费专项(DUT17ZD220)

摘　　要：中心支撑钢框架结构是一种典型的双重抗侧力体系,在强震作用下支撑失效会引发结构承载力和刚度的折减,其复杂的恢复力模型使得此类结构抗震性能的评估成为难点。为解决该问题,提出了多层中心支撑钢框架结构储备体系参数的概念及其计算方法,即通过对中心支撑钢框架结构进行推覆分析,将结构转化为等效单自由度体系,同时确定整体结构体系失效过程,进而确定储备体系和储备参数。结合中心支撑钢框架结构延性需求谱,建立了考虑能力储备的多层结构抗震性能简化评估方法,即“能力储备法”,该方法可有效评估中心支撑钢框架结构体系抗倒塌性能、延性与变形。采用该方法分析了2个5层中心支撑钢框架结构的抗震性能,并与非线性时程分析结果进行对比。分析表明,能力储备法可对多层中心支撑钢框架结构层间延性和顶点位移进行较准确的预测。Steel concentrically braced frame （CBF） is a typical kind of dual system. It is difficult to evaluate the seismic performance of CBFs because of the complex feature of restoring force of CBFs which contains a substantial decrease in strength and stiffness after brace failure subjected to strong earthquake loads. To solve this problem, the concept and assessment procedure of reserve capacity parameters of multi-degree of freedom （MDOF） CBFs were presented. Pushover analysis was performed to transform the MDOF structure to the SDOF system and the structural failure mode was identified. The reserve capacity parameters representing strength and stiffness ratios between reserve system and primary system were also established. A simplified procedure for estimating the collapse performance, ductility and displacement response of MDOF CBFs with reserve capacity was constructed combining with the ductility demand spectra. This method is called ＇reserve capacity method＇. A reasonable accuracy was demonstrated by comparing the results of ductility demands and roof displacements of proposed method with the results obtained by non- linear dynamic analyses of two 5-story test buildings. The results show that the reserve capacity method is capable of predicting seismic performance of MDOF CBFs.

关 键 词：中心支撑钢框架结构 等效单自由度体系 储备体系 抗震性能 抗倒塌能力 能力储备 

分 类 号：TU391[建筑科学—结构工程] TU311.3