高层钢框架支撑结构多尺度风致疲劳分析方法  

Multi-scale wind-induced fatigue analysis method of high-rise steel braced frame structure

作　　者：方钊[1] 李爱群[1,2] 李万润[1,3] 周艳春[1] Fang Zhao;Li Aiqun;Li Wanrun;Zhou Yanchun(School of Civil Engineering, Southeast University, Nanjing 210096,China;School of Civil and Transportation Engineering, Beijing University of Civil Engineering and Architecture, Beijing 100044, China;Institution of Earthquake Protection and Disaster Mitigation, Lanzhou University of Technology, Lanzhou 730050, China)

机构地区：[1]东南大学土木工程学院,南京210096 [2]北京建筑大学土木与交通工程学院,北京100044 [3]兰州理工大学防震减灾研究所,兰州730050

出　　处：《东南大学学报（自然科学版）》2017年第1期137-141,共5页Journal of Southeast University：Natural Science Edition

基　　金：国家自然科学基金重点资助项目(51438002);国家自然科学基金资助项目(51278104);中国博士后科学基金资助项目(2015M571641)

摘　　要：为了研究高层钢结构风致疲劳性能,提出了一种由整体尺度到局部节点尺度再到局部焊缝尺度的结构多尺度疲劳分析方法.选取某高层钢框架支撑结构为实际工程,模拟了相应的风荷载,通过建立结构的多尺度有限元模型,对模型进行时程分析,确定了结构应力较为集中的梁柱节点,并得到其应力集中的区域.然后,采用热点应力法对裂纹萌生寿命进行评估,并研究了单元类型及网格划分尺寸对结果的影响.结果表明:该结构底层边跨梁柱节点内侧梁上翼缘板的侧下部易产生较大的应力集中而萌生疲劳裂纹;对于焊缝附近的网格划分类型来说,线性单元及网格尺寸4 mm已基本满足精度需要;该工程的疲劳裂纹萌生寿命为335 a.To study the wind-induced fatigue performance of the high-rise steel structures,a structural multi-scale fatigue analysis method,which is from the global scale to the local joint scale and then to the local weld scale,is proposed.A high-rise steel braced frame structure is selected as the practical engineering example and the corresponding wind loading is simulated.Through the establishment of the multi-scale finite element model,the time-history analysis is performed.The beam-to-column joint with more concentrated stress in this structure is determined and the stress concentration zone in this welded joint is obtained.Then,the crack initiation life is evaluated by the hot spot stress method and the effects of the element type and the meshing size on the results are studied.The results show that,in this structure,the lower side span location in the frame beam upper flange of the ground floor beam-to-column joint is easy to produce high stress concentration and initiate fatigue cracks.As for the meshing style near welds,the linear element and the meshing size of4mm are basically satisfied with the precision requirements.The fatigue life of the project is335a.

关 键 词：高层钢结构 梁柱焊接节点 风致疲劳 多尺度 

分 类 号：TU973[建筑科学—结构工程]