防屈曲耗能支撑研究与应用的新进展

防屈曲耗能支撑是一种性能优良的新型耗能减震构件。本文阐述了防屈曲耗能支撑的构成和基本原理,根据约束构件的不同材料形式,将防屈曲耗能支撑划分为混凝土约束型防屈曲耗能支撑、全钢型防屈曲耗能支撑和装配式防屈曲耗能支撑。分别介绍了防屈曲耗能支撑的类型与性能、防屈曲耗能支撑框架分析与子结构试验,以及防屈曲耗能支撑在工程中的应用情况和标准化。指出了防屈曲耗能支撑研究和推广应用中存在的问题,给出了今后研究与应用的建议。     

运用防屈曲支撑的混凝土框架结构的抗震性能研究

简要介绍地震安全社区的实现途径以及防屈曲支撑的构成和性能参数。运用ABAQUS软件对有无安装防屈曲支撑的钢筋混凝土框架模型进行动力时程分析,总结分析防屈曲支撑对钢筋混凝土框架结构的减震效果。结果表明,防屈曲支撑能大大降低钢筋混凝土框架结构在罕遇地震作用下的层间位移角,提高建筑物抗震性能,使地震安全社区中抗震设防烈度为Ⅶ度的建筑物能够抵御Ⅷ度罕遇地震。     

二重钢管防屈曲耗能支撑的有限元分析

设计了12组41种二重钢管防屈曲耗能支撑试件,应用有限元软件ABAQUS对其进行了有限元分析,研究了径厚比、约束比、长细比和边界条件对支撑性能的影响.分析结果表明:二重钢管防屈曲耗能支撑的径厚比取值不大于24、约束比的取值不小于3时,支撑的滞回曲线饱满、稳定;当支撑的长细比增加时,可以通过提高约束比来避免支撑发生整体屈...     

新型铝合金耗能支撑屈曲约束条件研究

在国外已进行的相关铝合金材料及其屈曲约束支撑(BRB)试验基础上,对铝合金耗能支撑(ALBRB)的受力性能进行了进一步的数值分析。主要目的是对ALBRB进行参数化研究,找出影响其整体及局部屈曲的关键因素。结果发现利用约束比设计BRB的传统方法不能充分考虑偏心距、初始缺陷的影响,采用安全系数法能克服这一问题。为开发适用于空间结构减震的新型ALBRB,设计了一种质量更轻、构造更简单、性能更稳定的ALBRB,并对其防屈曲性能进行了理论推导和数值模拟。结果表明新型ALBRB单调加载下稳定性能良好,循环加载下其滞回曲线饱满稳定具备良好的耗能能力,对于大跨空间结构抗震应用具有积极意义。     

新型铝合金耗能支撑屈曲约束条件研究

在国外已进行的相关铝合金材料及其屈曲约束支撑(BRB)试验基础上,对铝合金耗能支撑(ALBRB)的受力性能进行了进一步的数值分析。主要目的是对ALBRB进行参数化研究,找出影响其整体及局部屈曲的关键因素。结果发现利用约束比设计BRB的传统方法不能充分考虑偏心距、初始缺陷的影响,采用安全系数法能克服这一问题。为开发适用于空间结构减震的新型ALBRB,设计了一种质量更轻、构造更简单、性能更稳定的ALBRB,并对其防屈曲性能进行了理论推导和数值模拟。结果表明新型ALBRB单调加载下稳定性能良好,循环加载下其滞回曲线饱满稳定具备良好的耗能能力,对于大跨空间结构抗震应用具有积极意义。     

巨型框架-耗能支撑结构的减震性能分析

对巨型框架-耗能支撑结构新体系进行了罕遇地震作用下的弹塑性时程分析,研究该体系的减震性能和耗能支撑的不同布置方式对结构的减震效果。结果表明:如果耗能支撑布置位置得当,可以用较少的耗能支撑个数达到较好的减震效果;巨型框架-耗能支撑结构不但可以减少原巨型框架-支撑结构的层间侧移,还可以减少其底部剪力和顶层加速度反应的峰值。     

变厚度钢板内芯防屈曲支撑试验研究

提出了一种变厚度钢板内芯防屈曲支撑（VTBRB）。设计了2个足尺变厚度钢板内芯防屈曲支撑试件,其中:1个试件在变厚度内芯端部设置加劲肋;另1个试件采用无肋式变厚度内芯。通过拟静力试验分析了2种内芯构造形式对变厚度钢板内芯防屈曲支撑的滞回性能、失效模式、受压承载力调整系数和累计塑性变形等的影响。研究表明:2个变厚度钢板内芯防屈曲支撑均表现较好的抗震耗能特性,其受压承载力调整系数均满足相关规范的限值要求。设置加劲肋可以减少变厚度内芯端部无粘结材料的磨损,并可以有效提高变厚度内芯防屈曲支撑的低周疲劳性能。     

间隙与支座类型对开孔三重钢管防屈曲耗能支撑性能的影响

利用ABAQUS有限元分析软件对开孔三重钢管防屈曲耗能支撑进行拉压循环荷载作用下的滞回性能、支撑的承载力及核心管的应力和变形进行模拟分析,研究了核心管与内外约束管之间的间隙和支撑的支座类型对支撑性能的影响。研究结果表明:当间隙为0 mm时,防屈曲耗能支撑在加载过程中出现套箍效应和整体屈曲现象;当间隙为1~2 mm时,加载过程中不出现套箍效应和屈曲现象;当间隙大于3 mm时,三钢管出现明显的弯曲,建议支撑的间隙控制在1~2 mm之间;当支座类型为铰接时,支撑还没屈服就已经屈曲;当支座类型为半刚接时,加载到38 mm时支撑发生屈曲;当支座类型为刚接时,支撑在加载的过程中不出现屈曲现象,在设计的过程中按铰接考虑是偏于安全的。     

耗能支撑钢筋混凝土框架结构抗震性能研究

本文通过普通钢筋混凝土框架、耗能支撑钢筋混凝土框架结构１／８比例模型的地震模拟振动台对比试验,研究两类框架结构在地震作用下的破坏形态和动力特征,揭示了耗能支撑钢筋混凝土框架结构良好的抗震性能;对试验模型进行了弹塑性时程分析,理论分析和试验结果符合较好;结合扬州电厂二期主厂房框排架结构,研究了其纵向框架结构采用耗能支撑体系时结构的抗震性能,为该类结构型式的工程应用提供依据     

耗能减震技术在抗震加固工程中的简化设计

介绍了阻尼器型屈曲约束支撑和阻尼器型屈曲约束钢板墙这两种耗能减震技术的简化设计方法,并通过这种简化设计方法使阻尼器型屈曲约束支撑这种耗能减震技术在抗震加固工程中的得到了应用,从案例分析结果看,这种耗能减震技术简化设计方法为结构抗震设计提供了可靠、便利的设计依据,是一种合理有效的抗震途径或结构振动控制技术手段,可应用于抗震加固工程的设计理论和分析。     

地震波参数对柱顶隔震体系的水平向减震性能影响研究

为了研究地震波参数对柱顶隔震体系的水平向减震性能的影响,选取台湾集集地震中8条地震波作为输入,进行了柱顶隔震体系模型的振动台试验。分析了柱顶隔震体系的水平向动力响应特点,研究了地震波的PGV/PGA、卓越周期、平均周期和断层距及幅值对其水平向减震性能的影响,并进行了数值模拟的对比分析。结果表明:柱顶隔震体系的水平向减震性能良好。相同地震强度下地震波参数的PGV/PGA、卓越周期、平均周期和断层距对柱顶隔震体系水平向减震性能的影响明显,其中:PGV/PGA的影响程度最大,可以作为主要的分析指标;随着地震动强度的增大柱顶隔震体系的水平向减震效果更加明显,地震动强度达到一定幅值后,减震率缓慢下降;与远场地震相比,近场地震不利于柱顶隔震体系的水平向减震性能的发挥,脉冲型近场地震作用下其减震效果更差。振动台试验结果与数值模拟结果基本一致,表明分析结果的可靠性。     

强震下水闸结构抗震性能分析

强震下的水闸结构抗震性能尚待深入研究,结合实际工程案例,运用UC-WCOMD有限元分析软件建立精细化的水闸计算模型,并分别采用Pushover法和时程分析法讨论水闸在强震作用下的抗震性能,结果表明:结合抗震设防目标,采用Pushover分析法评估水闸的抗侧能力,并采用弹塑性时程分析方法进行强震下的抗震性能校核,是值得推荐的研究方法。     

Dynamic buckling of braces in concentrically braced frames

Axially loaded members might experience compressive forces above their static buckling capacity because of dynamic buckling under rapid shortening. Although the subject is studied in the context of engineering mechanics, it has not been thoroughly investigated in the field of earthquake engineering. Such dynamic overshoots in the compressive capacity can also be observed for braces of concentrically braced frames (CBFs) during earthquakes. Consequently, a comprehensive investigation is conducted in this study regarding the effects of dynamic buckling of braces on the seismic behavior of steel CBFs. After providing a theoretical background, recent dynamic experiments on braces and CBFs are simulated and discussed to investigate the occurrence of dynamic overshoot during these tests. Eight archetype CBFs are then designed, modeled, and subjected to a large set of ground motions to provide a quantified insight on the frequency and anticipated level of dynamic overshoot in the compressive capacity of braces during earthquakes. Results of a total of 1600 nonlinear time history analyses revealed that dynamic overshoots occur frequently in braces and affect the behavior of CBFs notably. Considerable increases are recorded in forces transmitted to other members of CBFs as a consequence of such dynamic overshoots. Importance of incorporating these dynamic overshoots in the capacity design procedure of columns, beams, and gusset plates is highlighted. Furthermore, results of a parametric study are presented and summarized in the form of a simple formula that can be used as a guide for estimating the level of dynamic overshoot.     

A simplified methd of evaluating the seismic performance of buildings

This paper presents a simplified method of evaluating the seismic performance of buildings. The proposed method is based on the transformation of a multiple degree of freedom (MDOF) system to an equivalent single degree of freedom (SDOF) system using a simple and intuitive process. The proposed method is intended for evaluating the seismic performance of the buildings at the intermediate stages in design, while a rigorous method would be applied to the final design. The performance of the method is evaluated using a series of buildings which are assumed to be located in Victoria in western Canada, and designed based on the upcoming version of the National Building Code of Canada which is due to be published in 2005. To resist lateral loads, some of these buildings contain reinforced concrete moment resisting frames,while others contain reinforced concrete shear walls. Each building model has been subjected to a set of site-specific seismic spectrum compatible ground motion records, and the response has been determined using the proposed method and the general method for MDOF systems. The results from the study indicate that the proposed method can serve as a useful tool for evaluation of seismic performance of buildings, and carrying out performance based design.     

海南农村民居抗震性能调查与研究

海南农村民居以砌体结构为主,具有门窗开口大、层高较高和整体性强等特点.为了研究分析这类民居的抗震性能与抗震对策,在收集大量当地农村民居样本的基础上,综合出典型结构模型,并对该典型模型及基于该模型的隔震模型和加强结构模型分别进行了模拟地震振动台试验.试验结果表明:隔震技术能明显降低结构地震反应,在高烈度地区应适当推广和运用.原结构模型基本满足7.5度设防标准.在8度大震作用下,结构遭遇严重破坏但未倒塌,说明其具有一定的抗倒塌能力.结构加固后,整体抗震性能得到了加强.结合试验结果,给出了相应对策与建议.     

钢筋混凝土框架地震破坏研究概述

关于钢筋混凝土结构的破坏过程,是当前建筑抗震设计与研究中提出的新问题,本文介绍了国内外钢筋混凝土构件非线性地震反应分析和破坏过程研究的进展,和钢筋混凝土框架地震破坏评价的定量描述方法,以及钢筋混凝土框架结构地震破坏过程模拟的最新研究动态,指出地震工程研究领域中研究钢筋混凝土框架结构破坏过程有效手段。     

规则钢筋混凝土异形柱框架结构的抗震性能研究

本文按现行规范及技术规程设计了设防烈度为8度的一个规则的钢筋混凝土异形柱框架,并进行了单向水平地震作用下的空间三维非线性地震反应分析,考查了异形柱框架结构在设防和罕遇地震水准下的整体抗震性能,对结构能否达到抗震设防目标进行了初步评价。结果表明,8度区按规范设计的结构在设防烈度及罕遇烈度地震作用下基本能够达到预期的抗震设防目标。     

Experimental study on the seismic performance of new sandwich masonry walls

Sandwich masonry walls are widely used as energy-saving panels since the interlayer between the outer leaves can act as an insulation layer.New types of sandwich walls are continually being introduced in research and applications,and due to their unique bond patterns,experimental studies have been performed to investigate their mechanical properties,especially with regard to their seismic performance.In this study,three new types of sandwich masonry wall have been designed,and cyclic lateral loading tests were carried out on five specimens.The results showed that the specimens failed mainly due to slippage along the bottom cracks or the development of diagonal cracks,and the failure patterns were considerably influenced by the aspect ratio.Analysis was undertaken on the seismic response of the new walls,which included ductility,stiffness degradation and energy dissipation capacity,and no obvious difference was observed between the seismic performance of the new walls and traditional walls.Comparisons were made between the experimental results and the calculated results of the shear capacity.It is concluded that the formulas in the two Chinese codes(GB 50011 and GB 50003) are suitable for the calculation of the shear capacity for the new types of walls,and the formula in GB 50011 tends to be more conservative.     

多点激励下LRB隔震桥梁地震反应分析

研究了地震地面运动多点激励,即空间变化效应对装有铅芯橡胶支座（Lead Rubber Bearing）的连续梁桥地震反应的影响。首先,利用三角级数法生成了拟合规范反应谱的多点人工地震动时程;然后利用非线性时程分析法数值仿真并比较了某五跨LRB隔震连续梁桥在一致激励、仅考虑地震动行波效应、仅考虑地震动部分相干效应、同时考虑行波和部分相干效应以及同时考虑行波、部分相干和局部场地土效应等七种工况下结构的减震效果。行波效应和部分相干效应对铅芯橡胶支座隔震桥梁影响不大,而局部场地土效应对该类桥梁的地震反应分析影响很大,应该引起重视。     

A study on the seismic behavior of a retrofitted building based on nonlinear static and dynamic analyses

This study describes the seismic performance of an existing five storey reinforced concrete building which represents the typical properties of low-rise non-ductile buildings in Turkey. The effectiveness of shear walls and the steel bracings in retrofitting the building was examined through nonlinear static and dynamic analyses. By using the nonlinear static analysis, retrofitted buildings seismic performances under lateral seismic load were compared with each other. Moreover, the performance points and response levels of the existing and retrofitting cases were determined by way of the capacity-spectrum method described in ATC-40 (1996). For the nonlinear dynamic analysis the records were selected torepresent wide ranges of duration and frequency content. Considering the change in the stiffness and the energy dissipation capacities, the performance of the existing and retrofitted buildings were evaluated in terms of story drifts and damage states. It was found that each earthquake record exhibited its own peculiarities, dictated by frequency content, duration, sequence of peaks and their amplitude. The seismic performance of retrofitted buildings resulted in lower displacements and higher energy dissipation capacity depending mainly on the properties of the ground motions and the retrofitting strategies. Moreover, severe structural damage (irreparable or collapse) was observed for the existing building. However, buildings with retrofit alternatives exhibited lower damage levels changing from no damage to irreparable damage states.