摘要
针对横向采用钢桁架的普通钢桁框结构易发生腹杆失稳破坏且延性和耗能能力较差的特点,提出在桁架跨中设置两边连接钢板的延性钢桁框结构,从而使得在多遇地震作用下钢板不屈曲,罕遇地震作用下仅钢板屈服耗能,非消能段桁架和柱保持弹性,可显著提高桁框结构的延性和耗能能力。基于有限元模型,对普通钢桁框结构和两边连接钢板式延性钢桁框结构进行精细化分析,重点研究了钢板高厚比、消能段长度、消能段与非消能段连接方式对其抗侧性能影响,分析了预期破坏模式中的两边连接钢板式延性钢桁框结构的受力特点和荷载-位移曲线特征。研究结果表明:合理设计的两边连接钢板式钢桁框结构的延性更好,且结构的初始刚度基本不降低;结构的延性随着钢板高厚比的增加而提高,建议高厚比取200～400;消能段长度取总跨度的20%～40%,由此可以大幅度提高结构的延性,且不会显著降低结构承载能力;消能段与非消能段的连接采用铰接,可提高结构的转动能力、延性和耗能能力。
Instability of diagonal members of transverse truss in truss moment frames usually leads to poor ductility and energy dissipation capacity. Thus, special truss moment frames with two-side connecting web plates, in which the web plates connect to chord members only in the mid-span of the trusses, are proposed. The steel plates do not buckle under frequent seismic actions, while yield and dissipate energy when subjected to severe earthquakes. Besides, the trusses, columns and the non-dissipating sections remain elastic. By doing so, the ductility and energy dissipation capacity of steel truss structures can be significantly improved. The traditional truss moment frames and the special truss moment frames with two-side connecting web plates are investigated by finite element analysis, focusing on the influences of height to thickness ratios, length of an energy dissipation section, and the connection types between the energy dissipation section and the non-dissipating sections on their structural behavior when subjected to lateral loads. Additionally, the mechanical characteristics and the load-displacement curves are analyzed. Analysis results show that the ductility of the well-designed special truss moment frames with two-side connecting web plates is improved and the initial stiffness of the structures shows little reduction. The ductility of the structure is improved with the increase of the height to thickness ratio of the web plates. Thus, the height to thickness ratio should be 200-400. When the length of the energy dissipation section is 20%-40% of the total span, the great improvement of the ductility could be achieved without compromising much of its bearing capacity. Simple connections between the energy-dissipating section and the non-energy-dissipating sections can increase the rotation capacity, ductility and energy dissipation capacity of the structure.
作者
甘丹
姚玉珊
谭永超
周绪红
GAN Dan;YAO Yushan;TAN Yongchao;ZHOU Xuhong(Key Laboratory of New Technology for Construction of Cities in Mountain Area ( Chongqing University)of Ministry of Education,Chongqing 400045,China;School of Civil Engineering,Central South University,Changsha 410075,China)
出处
《建筑结构学报》
EI
CAS
CSCD
北大核心
2018年第S2期86-94,共9页
Journal of Building Structures
基金
国家重点研发计划(2016YFC0701201)
关键词
钢结构
桁框结构
两边连接钢板
消能段
延性
steel structure
truss moment frame
two-side connecting web plates
energy dissipation segment
ductility
