偏心支撑钢框架耗能梁段的设计

偏心支撑钢框架既具有较大的抗侧刚度,同时在大震作用下又具有很好的延性,介绍了偏心支撑钢框架中重要构件耗能梁段的设计方法。     

《钢结构设计规范》修订的建议

本文介绍了"对柱计算长度系数的一点认识","梁柱连接计算方法的改进","日本连接系数新规定","支撑设计方法的修订","忽略偏心弯矩的设计"和"节点域剪切变形计算",供修订钢结构设计规范参考.     

美国ANSI/AISC SSPEC-2002《钢结构建筑抗震设计规定》介绍(4)

20 0 2年 1月 31日 ,美国钢结构协会 (AISC)和AISC规范委员会正式批准发布《钢结构建筑抗震设计规定》。本文为《钢结构建筑抗震设计规定》介绍 (3)之续篇 ,对“规定”中“钢结构建筑”部分的第 13～ 16章节 ,包括特殊中心支撑抗弯框架 (SCBF)、普通中心支撑抗弯框架 (OCBF)和偏心支撑抗弯框架 (EBF)方面的有关内容进行了介绍并作了必要的说明。     

偏心支撑框架的设计计算方法

我国《建筑抗震设计规范》(GB5 0 0 11- 2 0 0 1)规定 ,8度以上宜采用偏心支撑 ,但我国至今没有一个自行设计的工程用过这种支撑。参考美国计算例题、相关规范 ,并依据我国规范 ,对偏心支撑框架的实际计算方法进行讨论 ,总结出适合我国规范和实际情况的偏心支撑框架设计计算方法。其中 ,重点介绍了各杆件的内力计算、消能梁段的设计、非消能梁段的设计、支撑的设计、柱的设计等 ,给工程设计提供理论基础和实用方法 ,有助于设计人员对该体系设计过程的了解和此种支撑的推广应用     

基于性能设计的高强钢组合Y形偏心支撑钢框架抗震性能研究

Y形偏心支撑钢框架结构中耗能梁段置于框架梁之外,耗能梁段变形不会对主体结构和楼板造成损害,震后易于修复更换。为了保证耗能梁段充分发挥塑性变形进行耗能,非耗能构件(框架梁、框架柱)截面设计往往过大,浪费钢材且限制了偏心支撑钢框架的应用。高强钢组合偏心支撑框架结构是指耗能梁段采用普通钢材(Q345钢),而框架梁、柱等非耗能构件采用高强度钢材(如Q460),不仅有效减小构件截面,而且可以推动高强钢在抗震设防区的应用,经济效益显著。采用基于性能的抗震设计方法设计了5层、10层、15层和20层的Y形偏心支撑钢框架结构,算例模型包括高强钢组合Y形偏心支撑钢框架和传统普通钢Y形偏心支撑钢框架,通过Pushover分析和时程分析研究该结构形式的承载力、抗侧刚度、层间侧移分布及破坏模式。研究表明:相同设计条件下,高强钢组合Y形偏心支撑钢框架结构与普通钢Y形偏心支撑钢框架结构的承载能力相近,但抗侧刚度略低,罕遇地震作用下二者具有相似的层间侧移分布和破坏模式。     

某高层框架支撑结构设计

本项目6#公寓楼为矩形钢管混凝土柱钢框架-支撑结构,介绍了该栋楼的结构整体计算和构件设计,对设计过程中的0.2VEK剪力调整、中心支撑和偏心支撑的设置、耗能梁段受剪承载力计算、柱计算长度选取等关键问题进行了探讨。     

高层建筑偏心支撑钢框架减轻地震响应分析

本文首先分析了偏心支撑钢框架中的关键构件－耗能连梁的弹塑性性能,提出了一种简化的屈服模型,并在此基础上编制一种新型的弹塑性时程分析程序。利用所编制的程序对两个典型算例进行了弹塑性时程分析,并对算例中偏心支撑框架和中心支撑框架两种结构的地震响应进行了比较。其结果表明,偏心支撑框架结构的地震响应要明显小于中心支撑框架结构的地震响应。     

基于抗震韧性的高强钢组合偏心支撑钢框架研究

将基于抗震韧性的设计理念引入高强钢组合偏心支撑钢框架结构.通过韧性设计,使得高强钢组合偏心支撑钢框架结构,在满足结构抗震目的的同时,结构构件参与结构抗震方式明确,主体构件不发生塑性破坏,耗能支撑或耗能梁段通过塑性变形吸收地震能量,同时,通过装配式建造,耗能构件易于更换,达到结构韧性抗震的目标.提出评价高强钢组合偏心支撑钢框架的评价指标.     

钢结构稳定设计讲座 第九讲 稳定设计中的支撑

本讲论述了钢结构稳定设计中支撑所起的作用和对支撑提出的要求,包括压杆的支撑,梁的支撑和框架的支撑,提出了支撑应具有的刚度和承载能力;还讨论了偏心设置的支撑对增强构件稳定承载能力的有效性。     

偏心支撑钢框架的设计

简述了偏心支撑钢框架结构的工作原理及特点,介绍了偏心支撑钢框架的设计计算方法,其中重点介绍了各杆件的内力计算：耗能梁段设计、非耗能梁段设计、支撑设计和框架柱设计,为工程设计人员提供了指导。     

Optimization of link member of eccentrically braced frames for maximum energy dissipation

An optimization method is presented for design of an eccentrically braced frame (EBF), which is used as a passive control device for seismic design of building frames. The link member between the connections of beams and braces of EBF is reinforced with stiffeners in order to improve its stiffness and plastic deformation capacity. We present a method for optimizing the locations and thicknesses of the stiffeners of the link member. The optimal solutions are found using a heuristic approach called tabu search. The objective function is the plastic dissipated energy before failure. The deformation of the link member under static cyclic loads is simulated using a finite element analysis software package. It is demonstrated in the numerical examples that the dissipated energy can be increased through optimization within small number of analyses.     

优化偏心支撑框架的连接件以获得最大耗能能力

给出偏心支撑框架(EBF)的优化设计方法,将其作为被动控制手段应用于建筑结构的抗震设计中。在EBF梁与支撑的连接件处设置加劲肋以提高其刚度和塑性变形能力。给出连接件加劲肋位置及厚度的优化设计方法,采用Tabu搜索算法求解最优解,其目标函数为破坏前的塑性能量耗散。采用有限元软件计算静态循环荷载作用下连接件的变形,结果显示,通过微单元优化可以提高连接件的耗能能力。     

偏心钢支撑-钢筋混凝土框架的侧移和地震反应

通过对偏心支撑钢筋混凝土框架试验结果的分析以及性能设计和抗震设计位移控制的比较,对其抗震设计中的变形和性能进行研究。为满足性能设计和三水准抗震设计要求,偏心支撑框架结构的侧移限值应比纯框架结构更严格,而且使得支撑的受压屈曲控制在第一水准位移后,将有利于抗震性能的改善。由于偏心钢支撑的作用,偏心支撑框架结构中柱的剪力明显减小,侧向刚度增大,从而有效地避免了框架结构在地震中柱的剪切破坏和过大的侧移。偏心支撑框架结构的地震反应如最大侧移、最大速度、最大加速度明显降低,结果表明,K型支撑是理想的抗震布置方式。     

Experimentally and analytically study on eccentrically braced frame with vertical shear links

The excellent hysteretic behavior of eccentrically braced frames (EBFs) using shear links have made these systems an effective alternative for both moment resisting frame as well as concentrically braced structures. Generally, horizontal shear links are located either at the middle or at the ends of the beam. However, large deformation of the shear links in those beam must be accepted under severe earthquakes. In those instance in which the beam have to remain elastic, vertical shear links should be designed underneath the beam thereby transferring the region of plastic deformation to location where they are tolerable and post‐earthquake repair or replacement of damaged parts is easier. In this paper, seismic behavior of vertical‐EBF (V‐EBF) have been considered experimentally and analytically. The required relation to design of the system have been proposed. In addition, to predict nonlinear behavior of V‐EBF systems, an analytical model including kinematic–isotropic strain hardening for shear, only kinematic strain hardening for moment, has been presented. Results showed a good convergence of the presented analytical model (with an upper bound for yielding surface to the V‐EBF) with experimental results.     

改良型梁柱节点用于D型偏心支撑钢框架在循环荷载作用下的滞回性能分析

偏心支撑框架结构体系是一种非常适合强震地区的抗震结构体系。D型偏心支撑钢框架结构是偏心支撑结构中常用的一种抗震耗能结构形式,其耗能梁段与柱直接相连,为了满足梁端抗弯承载力的设计要求和保证耗能梁段充分发展剪切塑性变形,一般需要对梁柱连接节点处采取一些加强措施。利用ANSYS有限元程序,针对传统节点比较分析了两种改良型梁柱连接节点的D型偏心支撑框架。分析结果表明,改良型节点的D型偏心支撑将耗能梁段外移不与柱直接相连,有良好的强度、刚度,不仅可以使剪切屈服的区域远离梁翼缘焊缝,而且可以放松钢柱对梁端部的变形约束,从而提高整个耗能梁段的耗能能力。     

Seismic testing and numerical analysis of Y‐shaped eccentrically braced frame made of high‐strength steel

In eccentrically braced frame made of high‐strength steel (HSS‐EBF), link and brace are made from conventional steel whereas other structural members use high‐strength steel. Using HSS for beams and columns in EBF can reduce steel consumption and increase economic efficiency. In this paper, one shake table test of a 1:2 scaled three‐story Y‐shaped HSS‐EBF (Y‐HSS‐EBF) specimen was carried out to study its seismic behavior underground motions with different peak ground accelerations. The dynamic properties, base shear force, displacement, and strain responses of the specimen were obtained from this test. In addition, the finite element models of two 10‐story Y‐HSS‐EBF buildings and one 10‐story conventional Y‐EBF building were evaluated for seismic effects. Nonlinear pushover and dynamic analyses were conducted to compare their seismic performance and economy. The results indicated that the specimen exhibited sufficient lateral stiffness and safety but suffered some localized damages. During the high seismic intensity earthquakes, the links of the test specimen were in inelastic to dissipate the earthquake energy, whereas other structural members remained in the elastic state. Under the same design conditions, Y‐HSS‐EBF used less steel than that of conventional Y‐EBF, which could reduce the amount of steel used in Y‐HSS‐EBF. The Y‐HSS‐EBF is a safe, dual system with reliable seismic performance.     

长耗能梁-偏心支撑机制对中心支撑钢框架结构抗震性能的影响

为研究地震作用下人字形中心支撑钢框架结构因支撑的部分失效导致的长耗能梁-偏心支撑机制对结构抗震性能的影响,基于ABAQUS建立了6层人字形中心支撑钢框架结构数值模型,开展了增量动力分析与易损性分析,对比了考虑与不考虑长耗能梁-偏心支撑机制时结构抗倒塌性能的差异,分析了结构的损伤演化过程。结果表明:长耗能梁-偏心机制改变了结构的失效过程,抑制了薄弱层的产生与发展,对结构抗震性能具有显著影响,算例结构的倒塌富余度提高20%以上; 梁的抗弯刚度对长耗能梁-偏心支撑机制具有一定影响,较大的刚度将不利于该机制的形成,降低了结构的抗倒塌能力; 在人字形中心支撑钢框架结构体系的设计与分析中,宜考虑长耗能梁-偏心支撑机制,否则将低估结构的抗倒塌性能。     

偏心支撑钢框架设计方法

着重阐述了消能梁段的设计方法 ,其中包括消能梁段的长度确定和截面选择 ,消能梁段的腹板加劲肋、连接和侧向支撑的设计。并对消能梁段以外其它构件的设计方法进行了介绍 ,以增强工程设计人员对该结构体系的了解。     

基于性能的几种钢结构支撑框架体系应用研究

采用SAP2000（V11.0.8 Advanced C）有限元分析软件,对12层钢结构框架建筑进行基于性能的Pushover能力谱法分析,考虑了纯框架、中心支撑框架、偏心支撑框架、隅撑支撑框架4种结构体系,结果表明：相对于纯框架和中心支撑框架,偏心支撑框架和隅撑支撑框架具有更优越的力学性能和更好的经济效益,设计中宜优先考虑使用。     

Successive collapse potential of eccentric braced frames in comparison with buckling-restrained braces in eccentric configurations

In the present research, the successive collapse potential of eccentric braced frames (EBF) in comparison with bucklingrestrained braces in eccentric configurations (BRBF-E) has been studied. Initially, five-story EBF and BRBF-E were analyzed and designed according to the guidelines of the American Institute of Steel Construction (AISC). Subsequently, the nonlinear dynamic analysis based on Unified Facilities Criteria (UFC) guidelines was used. The Alternate Path Method was used in the mentioned structures with various cases for removed columns. Both critical cases and successive collapse potential through values such as Impact Factor for columns, the end point vertical displacement of removed column and Demand-Capacity Ratio for link beams have been specified. The results indicate that removing edge columns caused further critical situation in EBF and BRBF-E compared to the other cases. The results elaborated that the BRBF-E has higher vulnerability than EBF. Furthermore, additional analysis were undertaken to establish the lateral stability of the removed columns. The results of the lateral stability analysis in one of the cases confirmed that the analyzed parameters were increased.