粘滞流体阻尼墙在高层结构减震中的研究与应用

在对粘滞流体阻尼墙力学特性及计算模型分析的基础上,研究其在高层建筑减震设计中的一些关键问题。以高烈度区江苏省宿迁市的一栋94.95m高的双塔建筑为工程背景,提出了阻尼墙减震体系的设防目标,并给出了减震分析的详细流程及阻尼墙的基本布置原则。通过对减震体系的非线性地震响应分析,优化了阻尼墙的初始布置方案,并在优化方案的基础上详细分析了减震体系的地震作用剪力、位移、能量耗散、加速度响应、附加阻尼比及构件进入塑性的先后顺序等问题,最后对减震体系的经济性进行了对比分析。分析表明：阻尼墙对高层建筑的抗震性能有很大的改善,相同数量阻尼墙的情况下,合理的配置方案能够提供更多的附加阻尼。研究为阻尼墙在高层建筑的减震设计中的应用提供了成功的工程案例,其设计思路可以为高层结构的减震提供有益的借鉴和参考。     

桥梁结构阻尼理论与阻尼参数确定

通过分析证实基于波动力学理论下粘滞阻尼理论及复阻尼理论的在杆的轴向振动及梁的横向振动中阻尼参数的一致性。通过引入应力波阻抗的概念,为结构振动分析计算中阻尼参数的选择提供一种实用性较强的方法,并应用这种方法来确定杆式结构和梁式结构的阻尼特性参数分布。     

黏滞阻尼墙在某双塔连体结构中的应用研究

黏滞阻尼墙是一种性能良好的消能减震部件。首先阐述了黏滞阻尼墙的基本构造和工作原理,在此基础上,研究了其在高层建筑减震设计中的一些问题。以河南省郑州市某高层双塔连体结构为工程背景,介绍了黏滞阻尼墙在结构分析模型中的实现方法,并通过三个方案计算比较了黏滞阻尼墙的不同布置方式对结构附加阻尼比、地震响应、双塔相对变形等指标的影响,并分析了其中的原因,提出了设计建议。研究结果为阻尼墙在高层建筑的减震设计中的应用提供了成功的工程案例,其设计思路可以为类似项目提供有益的借鉴和参考。     

高烈度区弹塑性软钢阻尼墙的减震设计研究

在对弹塑性软钢阻尼墙力学特性及计算模型分析的基础上,研究其在高烈度区进行减震设计中的应用,分析表明软钢阻尼墙对高烈度区高层建筑的抗震性能有很大的改善,该研究为高烈度区建造高层建筑提供了新的设计方法和思路。     

防屈曲钢板阻尼墙在云南省第一人民医院项目中的应用

探讨防屈曲钢板阻尼墙在高烈度区域高层建筑结构的布置原则及布置方法,以实现阻尼墙减震、抗震的最佳效果。介绍防屈曲钢板阻尼墙的构造要求。提出附加阻尼比的计算流程,并通过非线性时程分析获得了附加阻尼比值。以云南省第一人民医院项目为例,验证了防屈曲钢板阻尼墙在实际工程中应用的可行性。     

基于黏滞阻尼墙的高层建筑结构集成优化设计

黏滞阻尼墙是一种效率高的新型建筑结构消能减振部件,对于地震响应和风振动响应均有较好的减振效果,其为结构提供附加阻尼比可降低结构构件内力,从而为结构的构件设计提供了优化空间。提出一种基于黏滞阻尼墙的高层建筑结构集成优化设计方法,依据高层建筑结构构件的抗震性能目标及构件尺寸控制条件,加入黏滞阻尼墙对结构构件进行优化。以某300 m带环带桁架的框架核心筒超高层建筑为例,优化布置黏滞阻尼墙并且进行结构构件优化设计。结果表明,黏滞阻尼墙对高层建筑结构集成的优化可为结构主体带来经济性。     

软钢阻尼墙的理论分析及数值模拟

简述了带缝软钢阻尼墙的特点和受力机理,通过ABAQUS软件对5种软钢阻尼墙进行了非线性分析,得出了各自的滞回曲线,由此进一步对比分析了其耗能能力和滞回特性.结果表明,带竖缝的软钢阻尼墙承受反复荷载时,改变了原有钢板依靠剪切变形的耗能方式,主要以缝间壁柱的弯曲变形进行耗能,具有良好的延性和滞回性能.试件ZNQ-2～试件ZNQ-5中,以ZNQ-4型软钢阻尼墙的耗能性能最佳.本文分析结果为软钢阻尼墙更深入的研究提供了基础资料.     

建筑结构粘弹性阻尼耗能研究

本文探讨了建筑结构的粘弹性动力特性,提出了一种对高层建筑结构振动下粘弹性动力特性进行分析的方法,并对分析结果进行机理分析。这些工作为阻尼材料在工程中的应用建立分析计算基础。     

试样激励下轻敲模式原子力声显微镜的非线性动力学特性

利用Euler-Bernoulli梁理论和DMT针尖-样品作用力模型建立了试样激励下轻敲模式原子力声显微镜(AFAM)系统的动力学方程,并应用非线性动力学分析方法对AFAM微悬臂梁的振动特性进行研究。通过合理改变超声激励幅值、超声激励频率和针尖-样品初始间距等模型参数模拟得到微悬臂梁的超谐波、次谐波、准周期和混沌振动现象,采用时间序列、频谱、相空间、Poincare截面和Lyapunov指数等方法对不同非线性振动特性进行表征。通过分析不同模型参数条件下微悬臂梁针尖-样品作用力特性,探索了微悬臂梁不同非线性振动现象的产生机制。此外,研究了AFAM微悬臂梁运动的分岔特性,发现当超声激励幅值和针尖-样品初始间隙连续变化时,周期、准周期和混沌运动交替出现。研究结果对AFAM系统非线性动力学行为分析和混沌振动控制提供了理论参考。     

平面内和偏心状态下钢板阻尼墙抗震性能对比研究

为研究钢板阻尼墙双向抗震性能,对2个设计参数相同的钢板阻尼墙在平面内和偏心状态下进行试验对比研究。提出采用非线性随动强化模型模拟钢板阻尼墙力学性能,模拟结果和试验结果很接近。通过试验与模拟结果对比研究可知,钢板阻尼墙在偏心状态下依然有良好的抗震性能,故所提出的非线性随动强化模型模拟钢板阻尼墙力学性能是可行的。     

带缝空心RC剪力墙结构动力特性试验研究及仿真分析

为了研究带缝空心钢筋混凝土剪力墙结构房屋的动力特性,进行了缩比为1∶3的6层模型房屋的动力特性试验及拟动力试验,获得了结构的周期、振型、阻尼比、动力放大系数等动力特性参数。在试验研究的基础上,利用有限元分析软件ANSYS对结构模型进行了模态分析,试验结果与ANSYS模拟结果吻合较好。研究结果表明,带缝空心钢筋混凝土剪力墙结构是一种介于框架结构和传统剪力墙结构的新型结构形式。     

超高层建筑黏滞阻尼器及屈曲约束支撑混合减振结构系统集成优化设计

总结分析了黏滞阻尼器(VD)与屈曲约束支撑(BRB)的基本性能,提出了附加阻尼虚拟VD模型,基于该模型发展了一种VD优先布置顺序分析方法,进而提出了基于附加阻尼虚拟VD模型的黏滞阻尼系统优化设计方法。对BRB各种应力状态进行了详细分析,提出了基于支撑应力水平分析的BRB布置方法;将两种减振装备混合布置在结构中,提出了一种实用的混合减振系统设计方法。结合一10层平面框架算例,对所提方法的准确性进行验证。最后以某超高层结构工程为例,针对不同期望阻尼比对结构进行混合减振集成优化设计,并对设计结果进行对比分析。研究结果表明, VD可以有效增大结构阻尼,降低结构地震响应,BRB用于替换应力较大支撑,可缩小支撑截面尺寸,降低结构成本。因此,混合减振结构具有高效的减振性能和良好的经济性,有较大的工程应用价值。     

黏滞阻尼器在高层短肢剪力墙结构中的应用

在研究黏滞阻尼器减震短肢剪力墙结构抗震设计方法的基础上,对黏滞阻尼器的安装位置和传统计算方法进行总结和改进,提出按照阻尼力与楼层剪力呈正比的方式分配阻尼系数的方法,并采用渐进法的思想实现对结构所需附加阻尼比更为精确的计算。结合工程设计实例,通过方案对比,对普通剪力墙结构、短肢剪力墙结构、短肢剪力墙＋黏滞阻尼器结构建立有...     

半漂浮式主梁钢管混凝土拱桥黏滞阻尼器减震设计

为研究大跨半漂浮体系中承式钢管混凝土拱桥黏滞阻尼器参数选取与减震效果,以某计算跨径320 m中承式钢管混凝土拱桥为工程背景,采用MIDAS/Civil软件建立有限元模型,在动力特性分析的基础上提出黏滞阻尼器减震方案,并基于非线性动力时程分析方法研究了黏滞阻尼器的参数选取与减震效果。结果表明:半漂浮体系中承式钢管混凝土拱桥的纵飘振型出现较早,振型参与质量所占比重大,黏滞阻尼器参数选取主要应考虑梁端纵桥向容许位移和阻尼器连接构件所能承受的阻尼力; 对相同的阻尼指数,主梁梁端最大纵桥向位移响应随着阻尼系数的增大呈非线性减小,阻尼器轴力随着阻尼系数的增大几乎呈线性增大; 阻尼指数在0.2～0.4之间变化时,阻尼指数越大,同时满足梁端位移与阻尼力要求的阻尼系数可选范围越大; 设置黏滞阻尼器后,梁端纵桥向位移响应显著减小,拱顶纵桥向位移有所增加,除拱顶处拱肋轴力略有减小外,其余各处轴力、剪力与弯矩均有所增加,但内力响应绝对值不大; 研究成果可为同类桥梁减震设计提供参考。     

Structural performance and cost analysis of wind-induced vibration control schemes for a real super-tall building

To evaluate different energy dissipation systems used to control wind-induced vibrations of a 456 m super-tall building in fluctuating wind excitations, the finite element (FE) method was employed to simulate the dynamic responses of the building. A series of wind tunnel pressure tests were conducted on a 1:450 scale model to determine the wind forces acting on the super-tall building. A FE model was also constructed and mass, damping and stiffness matrices were subsequently formulated as an evaluation model for numerical analysis. The evaluation model was further simplified to a state reduced-order system using the state order reduction method. Three different vibration control schemes, namely a tuned mass damper (TMD) system, a system containing only nonlinear viscous dampers and a hybrid control system combining TMD and viscous dampers, were examined through simulations with respect to their effectiveness in reducing the accelerations at the top of the building. Furthermore, a cost evaluation was conducted to determine the most economical structural design and vibration control scheme. The results show that the wind-induced vibrations of the analysed building can be controlled effectively by all the three examined schemes, while the hybrid control scheme and the scheme containing only viscous dampers further reduce the wind-induced vibration to satisfy a more stringent criterion for a six-star hotel. In addition, the hybrid vibration control scheme is also the most cost-effective among the examined schemes.     

Seismic isolation design of the San Bernardino County Medical Center replacement project

The San Bernardino County Medical Center Replacement Project, located in Colton, California, consists of six separate building structures containing a total of approximately 920 000 ft² of floor space for hospital and support services. Five of the six buildings will be base isolated. Each of the five base isolated buildings is of different size and configuration, ranging from a six story, 360 000 ft² curved front Nursing Tower to a two story, 24 000 ft² rectangular shaped Central Plant building. The building structures will be framed with structural steel, utilizing concentric braced frames as the lateral force resisting system. The design ground motion for the site, which is located 3 km and 15 km from the San Jacinto and San Andreas faults respectively, is very severe. A base isolation system has been designed for this facility which will provide an essentially elastic building response to the design strong ground motion. The base isolation system is a hybrid passive energy dissipation system consisting of both linear and nonlinear and high damping rubber bearings along with viscous damping devices located at the base of the structure. The high damping rubber bearings provide both lateral stiffness which governs the fundamental period of vibration of the system, and hysteretic damping, while the viscous damping devices provide velocity dependent damping which serves to control overall building displacements. This will maximize the probability that this essential facility will remain fully operational after a major earthquake. Design criteria, structural analysis and design methodologies, and construction details are presented and discussed. The response of one of the base isolated structures is calculated utilizing actual recorded ground motions from the 1994 Northridge earthquake.     

宿迁市府苑小区综合楼隔震分析

宿迁市府苑小区综合楼位于 8度区 ,设计基本地震加速度值为 0 3 0 g ,为 6层底部框架砌体结构 ,平面呈三折线形。工程采用基础隔震技术进行结构设计 ,隔震层由橡胶隔震支座、滑移支座、粘滞消能器组成。对隔震体系空间模型的时程分析表明 :采用基础隔震措施可显著降低上部结构的地震作用 ;设置粘滞消能器能较好地解决降低上部结构的地震作用和限制隔震层位移之间的矛盾 ,有效地消除结构的扭转效应     

Multiperformance optimization design of a hybrid vibration mitigation system for super high‐rise buildings to improve earthquake resistance

A structure must meet many performance requirements to survive an earthquake. For a super high‐rise structure, the dominant control performance metric is stiffness when considering earthquake resistance because the lateral displacement of the structure often does not meet the requirements of the code even if the structure meets strength requirements. For moderate and major earthquakes, stiffness and strength play a leading role jointly. Viscous damper (VD) and buckling restraint brace (BRB) are damping devices that are commonly used in modern engineering. The efficiencies of these devices are different for different situations, and combining them can yield improved structural vibration mitigation. In this study, the performances of VD and BRB are summarized. A kind of virtual VD model with an additional damping ratio is proposed on the basis of which a VD priority placement analysis method is developed, and an optimal design is proposed. A detailed analysis of various stress states of a BRB is also performed, and a BRB arrangement method based on brace stress level analysis is proposed. The two kinds of vibration damping equipment are combined in the structure, and a practical design method for a hybrid vibration damping system is proposed. The accuracy of the proposed method is verified by considering a 10‐story plane frame. Finally, a hybrid vibration mitigation design for different objective damping ratios is performed for a super tall building project, and the design results are compared. The analysis results show that a VD can effectively increase structural damping and reduce the seismic response of the structure. A BRB is used to replace supports that experience high stress and reduce their section size, thereby reducing costs. Therefore, the proposed hybrid vibration damping structure is cost effective while providing good energy dissipation and is thus promising for engineering applications.     

A fractional-spectral method for vibration of damped space structures

Based on the theory of fractional calculus and the spectral theory of vibration, a new spectrally formulated finite element method of analysis is developed which is capable of making accurate predictions of the dynamic response of structures with added dampers. The frequency-dependence damping characteristic of structural materials can be modelled accurately using the fractional derivative model. It is shown that the proposed method can be extended to develop a nonlinear damping element which can be used to model structural dampers. The approach has an advantage over the usual viscous treatment, which appears to lack physical motivation. The nonlinear damping solution is shown graphically, and the consistency of method is investigated. Using a computer program, the proposed formulation has been used to derive the dynamic response of a tall structure with added viscoelastic dampers.     

加荷频率对土体动力特性影响的试验分析

通过在不同的振动频率情况下,试验场地土的应力-应变曲线、动模量曲线和阻尼比曲线与振动频率的关系,讨论了振动频率对粘性土的动力特性的影响。结果表明:在这4种频率作用下,粘性土的动本构关系均服从双曲线模型;振动频率在应变较小时对土的动模量影响较小、在应变较大时影响较大;振动频率对于粘性土的阻尼比则具有较大的影响。