耗能段腹板高厚比对Y型偏心支撑钢框架滞回性能影响的试验研究   总被引：1，自引：0，他引：1  

于安林  赵宝成  李仁达  沈淼 《地震工程与工程振动》2009,29(6)

Y型偏心支撑钢框架是偏心支撑结构中抗震耗能的结构形式之一,为了研究Y型偏心支撑钢框架中耗能梁段腹板高厚比对结构滞回性能的影响,进行了2榀1/3缩尺Y型偏心支撑钢框架的低周反复荷载试验.本文主要介绍了试验过程,分析了Y型偏心支撑钢框架在循环荷载作用下的破坏机理、滞回性能、延性、刚度退化规律以及耗能能力.试验结果表明:Y型偏心支撑钢框架延性好、耗能能力强,耗能梁段腹板高厚比的改变对Y型偏心支撑钢框架强度、刚度以及耗能能力具有较大的影响.耗能梁段腹板高厚比设计得合理,Y型偏心支撑钢框架侧向刚度较大,可以满足在小震或中震作用下的结构变形要求,在大震作用下提供良好的变形能力和耗散地震能量的功能.  相似文献   

钢筋混凝土框架结构层间位移角与构件变形关系研究   总被引：2，自引：0，他引：2  

蒋欢军  吕西林 《地震工程与工程振动》2009,29(2)

层间位移角已作为检验建筑结构抗震性能的主要指标之一而被广泛应用。为实现该指标在钢筋混凝土框架结构基于位移的抗震设计中的应用,研究了层间位移角与构件变形之间的关系。首先,采用对部分子结构的弹性理论分析得到了弹性阶段梁变形对层间位移角贡献比例的计算公式。接着,采用对15层钢筋混凝土框架整体结构的非线性地震反应计算结果的统计分析得到了在塑性阶段梁变形对层间位移角的贡献比例回归计算公式。所建立的计算公式反映了梁与柱的相对刚度和强度比例、层闽塑性变形程度的影响。最后,应用该方法进行了一算例分析,计算结果和试验结果比较一致。利用本文提出的计算方法可以方便地把对框架结构的层间位移需求转变为对梁、柱构件的变形要求。  相似文献   

Local fracture‐induced phenomena in steel moment frames     

Janise E. Rodgers  Stephen A. Mahin 《地震工程与结构动力学》2009,38(2):135-155

Brittle fractures were observed at the welded beam‐to‐column connections of a number of steel moment frame buildings following the M6.7 1994 Northridge earthquake. Such fractures cause a rapid loss of connection strength and stiffness, as well as a sudden release of the strain energy stored by the connection at the time of fracture. Immediately following the fracture, a number of highly transient phenomena occur locally in the members adjacent to the connection, as well as globally in the structure as a whole. Four significant local phenomena were observed locally during shaking table tests of a one‐third scale, two‐story, one‐bay steel moment frame in which quasi‐brittle beam‐to‐column fractures occurred: (a) change in beam deflected shape; (b) change in moment distribution in adjacent members; (c) generation and propagation of elastic waves; and (d) initiation of dynamic modal response at the member level. Owing to the highly transient nature of these phenomena, they were observed to have second‐order effects on overall behavior of the system. In comparison, the reductions in local strength and stiffness caused by the fractures had much more significant effects on system behavior. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

Control of the earthquake and wind dynamic response of steel‐framed buildings by using additional braces and/or viscoelastic dampers     

Fabio Mazza  Alfonso Vulcano 《地震工程与结构动力学》2011,40(2):155-174

The insertion of steel braces equipped with viscoelastic dampers (VEDs) (‘dissipative braces’) is a very effective technique to improve the seismic or wind behaviour of framed buildings. The main purpose of this work is to compare the earthquake and wind dynamic response of steel‐framed buildings with VEDs and achieve optimal properties of dampers and supporting braces. To this end, a numerical investigation is carried out with reference to the steel K‐braced framed structure of a 15‐storey office building, which is designed according to the provisions of Eurocodes 1 and 3, and to four structures derived from the first one by the insertion of additional diagonal braces and/or VEDs. With regard to the VEDs, the following cases are examined: absence of dampers; insertion of dampers supported by the existing K‐braces in each of the structures with or without additional diagonal braces; insertion of dampers supported by additional diagonal braces. Dynamic analyses are carried out in the time domain using a step‐by‐step initial stress‐like iterative procedure. For this purpose, the frame members and the VEDs are idealized, respectively, by a bilinear model, which allows the simulation of the nonlinear behaviour under seismic loads, and a six‐element generalized model, which can be considered as an in‐parallel‐combination of two Maxwell models and one Kelvin model. Artificially generated accelerograms, whose response spectra match those adopted by Eurocode 8 for a medium subsoil class and for different levels of peak ground acceleration, are considered to simulate seismic loads. Along‐wind loads are considered assuming, at each storey, time histories of the wind velocity for a return period T_r=5 years, according to an equivalent spectrum technique. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

利用天测与测地VLBI观测建立天球与地球参考架   总被引：2，自引：0，他引：2  

王广利  李金岭  钱志瀚  周瑞仙 《测绘学报》2000,29(2):114-117

本文讨论了利用天测与测地 VLBI观测建立天球与地球参考架过程中所面临的问题及解决的技术途径 ,涉及天球参考架与地球参考架原点与定向的确定、地球参考架时间演变的确定等。并通过实测数据分析与结果比对证明解决途径的有效性。  相似文献   

Design and full‐scale experimental evaluation of a seismically endurant steel buckling‐restrained brace system          下载免费PDF全文

Morteza Dehghani  Robert Tremblay 《地震工程与结构动力学》2018,47(1):105-129

This paper presents the results of 12 full‐scale tests on buckling‐restrained brace (BRB) specimens. A simple‐to‐fabricate all‐steel encasing joined by high‐strength bolts was used as the buckling‐restrainer mechanism. Steel BRBs offer significant energy dissipation capability through nondeteriorating inelastic response of an internal ductile core. However, seismic performance of BRBs is characterized by interaction between several factors. In this experimental study, the effects of core‐restrainer interfacial condition, gap size, loading history, bolt spacing, and restraining capacity are evaluated. A simple hinge detail is introduced at the brace ends to reduce the flexural demand on the framing components. Tested specimens with bare steel contact surfaces exhibited satisfactory performance under the American Institute of Steel Construction qualification test protocol. The BRBs with friction‐control self‐adhesive polymer liners and a graphite‐based dry lubricant displayed larger cumulative inelastic ductility under large‐amplitude cyclic loading, exceeding current code minimum requirements. The BRB system is also examined under repeated fast‐rate seismic deformation history. This system showed significant ductility capacity and remarkable endurance under dynamic loading. Furthermore, performance is qualified under long‐duration loading history from subduction zone's megathrust type of earthquake. Predictable and stable performance of the proposed hinge detail was confirmed by the test results. Internally imposed normal thrust on the restrainer is measured using series of instrumented bolts. Weak‐ and strong‐axis buckling responses of the core are examined. Higher post‐yield stiffness was achieved when the latter governed, which could be advantageous to the overall seismic response of braced frames incorporating BRBs.  相似文献   

A rational H∞‐norm–based approach for the optimal design of seismically excited reinforced concrete frames     

《地震工程与结构动力学》2018,47(6):1522-1543

A rational approach is presented for minimizing the dynamic response of reinforced concrete framed structures forced by a seismic base acceleration. Reference is made to EC8 regulations, but the presented approach may in principle be applied to structures ruled by any regulation code. Governing equations are set in the frequency domain (and not in the periods domain as usual) so as to enable the adoption of sound approaches for analysis and design of dynamic structures that are typical of automatics. Among these, a novel usage of the H_∞‐norm concept is proposed that determines a rational design approach capable to minimize the structural response with reference to any quantity of engineering interest, eg, the overall compliance and the displacement of a specific point or the interstorey drift. A numerical investigation on a 6‐storey 3‐bay frame is performed, and relevant analysis and design results are presented in much detail to validate the theoretical framework.  相似文献   

不同支撑形式高强钢组合偏心支撑抗震性能研究          下载免费PDF全文

王峥  李慎 《世界地震工程》2020,(3):080-92

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。  相似文献   

Rocking damage‐free steel column base with friction devices: design procedure and numerical evaluation          下载免费PDF全文

Fabio Freddi  Christoforos A. Dimopoulos  Theodore L. Karavasilis 《地震工程与结构动力学》2017,46(14):2281-2300

Earthquake‐resilient steel frames, such as self‐centering frames or frames with passive energy dissipation devices, have been extensively studied during the past decade, but little attention has been paid to their column bases. The paper presents a rocking damage‐free steel column base, which uses post‐tensioned high‐strength steel bars to control rocking behavior and friction devices to dissipate seismic energy. Contrary to conventional steel column bases, the rocking column base exhibits monotonic and cyclic moment–rotation behaviors that are easily described using simple analytical equations. Analytical equations are provided for different cases including structural limit states that involve yielding or loss of post‐tensioning in the post‐tensioned bars. A step‐by‐step design procedure is presented, which ensures damage‐free behavior, self‐centering capability, and adequate energy dissipation capacity for a predefined target rotation. A 3D nonlinear finite element (FE) model of the column base is developed in abaqus . The results of the FE simulations validate the accuracy of the moment–rotation analytical equations and demonstrate the efficiency of the design procedure. Moreover, a simplified model for the column base is developed in OpenSees . Comparisons among the OpenSees and abaqus models demonstrate the efficiency of the former and its adequacy to be used in nonlinear dynamic analysis. A prototype steel building is designed as a self‐centering moment‐resisting frame with conventional or rocking column bases. Nonlinear dynamic analyses show that the rocking column base fully protects the first story columns from yielding and eliminates the first story residual drift without any detrimental effect on peak interstory drifts. The study focuses on the 2D rocking motion and, thus, ignores 3D rocking effects such as biaxial bending deformations in the friction devices. The FE models, the analytical equations, and the design procedure will be updated and validated to cover 3D rocking motion effects after forthcoming experimental tests on the column base. Copyright © 2017 John Wiley & Sons, Ltd.  相似文献   

考虑悬链线效应的RC框架结构鲁棒性分析     

崔双双  魏中飞  乔泽惠  林涛  陈伟宏 《地震工程与工程振动》2021,41(1):100-112

为了充分反映结构的抗连续倒塌能力,文中基于能量原理,将结构倒塌时消耗能量与屈服时消耗能量之比定义为考虑悬链线效应的结构鲁棒性指标.首先进行一榀1/2缩尺的RC平面框架的连续倒塌试验,得到了具有双峰值点的荷载-位移曲线.基于试验数据对有限元模型进行验证与校准.进一步建立了 18 个RC 平面框架结构数值分析模型,研究了中...  相似文献