消能支撑框架结构的非线性分析

本文介绍了六榀钢筋混凝土支撑框架模型（两榀为普通支撑框架，另四榀为消能支撑框架）在低周反复荷载作用下的工作性能和试验结果；编制了非线性程序，对试验模型进行了计算分析，计算结果和试验实测值符合较好；另外还计算了两榀足尺消能支撑框架结构，研究不同的消能器滑移荷载对结构抗震能力的影响，结果表明消能支撑框架结构具有良好、稳定的抗震性能。     

消能支撑框架结构设计方法探讨

本文提出了一种新的消能支撑框架结构设计方法，该方法能够实现罕遇地震下结构的目标位移控制，其主要设计思路是框架主体结构按非抗震设计或降低烈度进行抗震设计，消能支撑则由罕遇烈度地震下满足给定层间位移角限值的优化计算来确定。本文还给出了一个15层框架结构的设计算例，并把本文方法的设计结果与按常规方法的设计结果进行了比较。     

复合型摩擦消能支撑减震体系的地震模拟振动台试验研究

介绍了装有复合型摩擦消能支撑的钢框架模型的地震模拟振动台试验，试验结果表明，复合型摩擦消能支撑能有效地减小结构的地震反应。     

框架结构消能支撑的减震优化方法

运用非线性规划中的复形法,对消能支撑框架结构中消能支撑的参数进行了优化,编制了适用性较好的计算机程序,并以一个６层钢筋混凝土框架作为算例,给出了在不同层间位移角限值下的优化结果。     

摩擦消能支撑钢框架结构的弹塑性地震反应时程分析

本文分析了摩擦消能支撑及框架主体结构弹塑性本构关系，并给出了动力时程分析的计算方法。同时，对六层钢框架模型做了各种工况下的地震反应时程分析。结果表明，摩擦消能支撑钢框架（FEDBF）比抗弯钢框架（MRF）的地震作用明显降低，尤其在强震作用下效果更加明显。     

体育场震后修复再建中混凝土结构消能减震设计研究

以往是用高层建筑防屈曲支撑的混凝土减震加固方法,以加固震后体育场混凝土结构的防屈曲支撑力为重点,存在的问题是未考虑结构不同部位节点的防屈曲消能减震支撑性能,加固效果差,需要深入研究混凝土结构建筑加固措施,提高震后体育场修复质量。研究采用基于性能和需求的消能减震设计方法,合理布置混凝土的消能支撑结构,在混凝土结构中底层节点设置防屈曲消能减震支撑,其他节点设置黏滞阻尼器,获取最佳阻尼器设置方案,提高结构减震加固效果。仿真实验说明,EL-Centro(NS)地震波和Newhall地震波情况下,所研究方法设计的消能减震新结构平均顶点侧移值分别比原结构小62 mm和110 mm;在不同震级的情况下,节点间位移角新结构小于原结构,说明该方法设计的体育场修复中混凝土结构减震稳定性强,是一种有效的减震加固方法。     

工程结构粘弹性消能支撑型式及设计参数的研究

针对工程中的实际需要,提出一些新型的粘弹性消能支撑型式,分析了它们的受力特点,推导了消能支撑变形的表达式,并给出了其控制力的计算公式;最后,研究了影响结构消能效果的设计参数,给出了设计参数合理的取值范围。     

宿迁市建设大厦消能减震设计

宿迁市建设大厦,21层,框架-抗震墙结构,按Ⅷ度(0．3g)进行抗震设防;由于建筑部分楼层层间位移超过《规范》要求,因此在部分楼层增设消能支撑,通过提高结构的附加阻尼比来降低结构的位移反应。整体结构的非线性时程分析结果表明,在框架-抗震墙结构中增设消能支撑,可以较为经济地控制结构薄弱层的位移,提高结构的抗震安全储备。本文可为高烈度区类似工程的设计提供借鉴。     

高层建筑用复合型摩擦消能支撑的设计试验和分析

本文介绍了复合型摩擦消能支撑的设计、试验及工作机理分析，并给出了消能支撑减震体系的分析方法。     

某大型复杂结构地震响应与控制研究

针对某大型复杂结构的地震响应及控制策略进行了研究。首先,建立该结构的整体有限元模型,采用Ritz向量法对结构进行模态分析,研究该复杂结构的振动特性,基于位能加权平均法求解了该复杂结构等效阻尼比;随后,研究了不同布置型式下粘滞消能支撑的受力特点和计算模型;最后.对该结构进行减振设计,分析了不同消能支撑布置形式下的减振效果。结果表明,采用消能减震装置能有效降低复杂结构的地震响应,且并不改变结构体型;同等减震效果前提下,采用人字形支撑比采用斜撑更为经济。本文工作可供类似的大型复杂结构减震设计参考和借鉴。     

D型耗能器偏心支撑结构的抗震性能试验研究

偏心支撑结构是一种高烈度地震区高层建筑钢结构合理的抗侧力体系,本文针对目前偏心支撑结构存在的不足,提出一种新型的框架支撑形式——耗能器偏心支撑;并将该单斜杆(D型)耗能器偏心支撑与支撑斜杆上不加设耗能器的D型偏心支撑结构进行了对比试验。验证了该新型框架支撑形式不仅可以减少耗能梁段吸收的地震能量,而且可以减小耗能梁段的破坏程度,从而减少震后修复工作量;它具有很好的变形能力和足够的抗侧移能力。文中同时给出了设计方法,并提出了改进措施。     

Seismic retrofitting of braced frame buildings by RC rocking walls and viscous dampers

A design procedure for seismic retrofitting of concentrically and eccentrically braced frame buildings is proposed and validated in this paper. Rocking walls are added to the existing system to ensure an almost uniform distribution of the interstorey displacement in elevation. To achieve direct and efficient control over the seismic performance, the design procedure is founded on the displacement‐based approach and makes use of overdamped elastic response spectra. The top displacement capacity of the building is evaluated based on a rigid lateral deformed configuration of the structure and on the ductility capacity of the dissipative members of the braced frames. The equivalent viscous damping ratio of the braced structure with rocking walls is calculated based on semi‐empirical relationships specifically calibrated in this paper for concentrically and eccentrically braced frames. If the equivalent viscous damping ratio of the structure is lower than the required equivalent viscous damping ratio, viscous dampers are added and arranged between the rocking walls and adjacent reaction columns. The design internal forces of the rocking walls are evaluated considering the contributions of more than one mode of vibration. The proposed design procedure is applied to a large set of archetype braced frame buildings and its effectiveness verified by nonlinear dynamic analysis.     

Hybrid simulation of a zipper‐braced steel frame under earthquake excitation

Hybrid simulation is a testing methodology that combines laboratory and analytical simulation to evaluate seismic response of complex structural framing systems. One or more portions of the structure, which may be difficult to model numerically or have properties that have not been examined before, are tested in one or more laboratories, whereas the remainder of the structure is modeled in software using one or more computers. These separate portions are assembled such that combined dynamic response of the hybrid model to excitation is computed using a time‐stepping procedure. A hybrid simulation conducted to examine the seismic response of a type of steel concentrically braced frame, the suspended‐zipper‐braced frame, is presented. The hybrid simulation testing architecture, hybrid model, test setup, solution algorithm, and the seismic response of the suspended‐zipper‐braced frame hybrid model are discussed. Accuracy of this hybrid simulation is examined by comparing hybrid and computer‐only simulations and the errors are quantified using an energy‐based approach. This comparison indicates that the deployed hybrid simulation method can be used to accurately model the seismic response of a complex structural system such as the zipper‐braced frame. Copyright © 2008 John Wiley & Sons, Ltd.     

Direct displacement-based seismic design of steel eccentrically braced frame structures

This paper details a direct displacement-based design procedure for steel eccentrically braced frame (EBF) structures and gauges its performance by examining the non-linear dynamic response of a series of case study EBF structures designed using the procedure. Analytical expressions are developed for the storey drift at yield and for the storey drift capacity of EBFs, recognising that in addition to link beam deformations, the brace and column axial deformations can provide important contributions to storey drift components. Case study design results indicate that the ductility capacity of EBF systems will tend to be relatively low, despite the large local ductility capacity offered by well detailed links. In addition, it is found that while the ductility capacity of EBF systems will tend to reduce with height, this is not necessarily negative for seismic performance since the displacement capacity for taller EBF systems will tend to be large. To gauge the performance of the proposed DBD methodology, analytical models of the case study design solutions are subject to non-linear time-history analyses with a set of spectrum-compatible accelerograms. The average displacements and drifts obtained from the NLTH analyses are shown to align well with design values, confirming that the new methodology could provide an effective tool for the seismic design of EBF systems.     

Shaking table test and numerical analysis of a 1：12 scale model of a special concentrically braced steel frame with pinned connections

<正>This paper describes shaking table tests of a 1:12 scale model of a special concentrically braced steel frame with pinned connections,which was fabricated according to a one-bay braced frame selected from a typical main factory building of a large thermal power plant.In order to investigate the seismic performance of this type of structure,several ground motion accelerations with different levels for seismic intensityⅧ,based on the Chinese Code for Seismic Design of Buildings,were selected to excite the model.The results show that the design methods of the members and the connections are adequate and that the structural system will perform well in regions of high seismicity.In addition to the tests,numerical simulations were also conducted and the results showed good agreement with the test results.Thus,the numerical model is shown to be accurate and the beam element can be used to model this structural system.     

Seismic design and test of gusset connections for buckling‐restrained braced frames

The corner gusset plates in a steel braced frame can be subjected to forces not only from the brace but also from the effects of the frame actions. In this study, several finite element models are constructed to analyze the gusset‐to‐beam and gusset‐to‐column interface forces. It is found that the frame actions affect the gusset interface force distributions significantly. A simplified strut model to represent the gusset plate is adopted to evaluate the frame action forces. In addition, the generalized uniform force method is adopted as it provides more freedom for designers to configure the gusset plate shapes than using the uniform force method. In this paper, a performance‐based design method is proposed. The gusset interface force demands take into account the combined effect of the brace maximum axial force capacity and the peak beam shear possibly developed in the frame. The specimen design and key results of a series of full‐scale three‐story buckling‐restrained braced frame (BRBF) hybrid tests are discussed. The gusset interface cracks observed at inter‐story drift greater than 0.03 radians can be well predicted by using the proposed design method. The BRBF tests and analyses confirm that the proposed design method is reasonable. The effectiveness of varying the width of gusset edge stiffeners in reducing the gusset tip stress concentrations is also investigated. This paper concludes with recommendations for the seismic design of BRBF corner gusset plates. Copyright © 2013 John Wiley & Sons, Ltd.     

屈曲约束支撑半刚性连接框架弹塑性地震位移简化计算

研究屈曲约束支撑半刚性连接框架弹塑性位移计算方法,为这种结构抗震设计提供依据.推导了屈曲约束支撑半刚性连接框架结构侧移刚度计算方法,通过计算屈曲约束支撑和半刚性连接在罕遇地震作用下的有效阻尼比,修正弹性设计反应谱,再利用修正后的设计反应谱进行结构弹塑性层间位移简化计算.通过与弹塑性时程分析对提出的计算方法进行验证.基于有效阻尼比的思想给出的弹塑性位移的简化计算方法可进行屈曲约束支撑半刚性连接框架罕遇地震下的抗震设计.     

Assessment of European seismic design procedures for steel framed structures

This paper assesses the fundamental approaches and main procedures adopted in the seismic design of steel frames, with emphasis on the provisions of Eurocode 8. The study covers moment-resisting as well as concentrically-braced frame configurations. Code requirements in terms of design concepts, behaviour factors, ductility considerations and capacity design verifications, are examined. The rationality and clarity of the design principles employed in Eurocode 8, especially those related to the explicit definitions of dissipative and non dissipative zones and associated capacity design criteria, are highlighted. Various requirements that differ notably from the provisions of other seismic codes are also pointed out. More importantly, several issues that can lead to unintentional departure from performance objectives or to impractical solutions, as a consequence of inherent assumptions or possible misinterpretations, are identified and a number of clarifications and modifications suggested. In particular, it is shown that the implications of stability and drift requirements as well as some capacity design checks in moment frames, together with the treatment of post-buckling response and the distribution of inelastic demand in braced frames, are areas that merit careful consideration within the design process.     

不同支撑形式高强钢组合偏心支撑抗震性能研究

耗能梁段作为偏心支撑结构的耗能元件,在大震作用下通过弹塑性变形吸收地震能量,保护主体结构处于弹性受力状态。现行规范基于强度的设计理论,为了保证耗能梁段进入塑性或破坏,梁柱构件需要进行放大内力设计,导致截面过大,而且基于强度的设计方法很难保证结构的整体破坏状态。目前,抗震设计越来越重视基于性能的设计思想,该方法能够评估结构的弹塑性反应。对于高强钢组合偏心支撑,其中耗能梁段和支撑采用Q345钢,框架梁柱采用Q460或者Q690高强度钢材,高强钢不仅带来良好的经济效益,而且能够推广高强钢在抗震设防区的应用。利用基于性能设计方法设计了4种不同形式的高强钢组合偏心支撑钢框架,包括K形、Y形、V形和D形,考虑4层、8层、12层和16层的影响。通过Pushover分析和非线性时程分析评估该结构的抗震性能,研究结果表明:4种形式的高强钢组合偏心支撑钢框架具有类似的抗震性能,在罕遇地震作用下,几乎所有耗能梁段均参与耗能,而且层间侧移与耗能梁段转角沿高度分布较为均匀。其中:D形偏心支撑具有最大的抗侧刚度,但延性较差,而Y形偏心支撑的抗侧刚度最弱,但延性最佳。     

高层钢结构基于均匀损伤设计的整体抗震能力提高方法

本文主要研究如何通过合理设计来提高高层钢结构的整体抗震能力。首先,给出了高层钢结构的非线性计算模型;其次,建立了高层钢结构在强地震动作用下的倒塌失效模式的极限状态判别准则;然后,通过模态pushover分析,研究了高层钢结构在水平地震作用下的损伤规律;最后,重点研究了高层钢结构的整体抗震能力的提高方法,提出了均匀损伤的设计方法,该方法通过消除结构的薄弱层,来达到提高高层钢结构的整体抗震能力的目的。通过对两栋20层的高层钢框架结构进行极限时程分析和极限pushover分析,验证了文中提出的均匀损伤的设计方法的可行性。本文的工作可为高层钢结构的抗地震倒塌设计提供参考依据。