高层减震结构地震响应及方案优化研究

针对某高层建筑结构,利用ETABS有限元分析软件建立计算模型,探讨原结构和设置黏滞阻尼器的减震结构在多遇地震作用下的抗震性能,通过进行五种黏滞阻尼器布设方案下结构响应的比较,以不同的控制函数为目标,进而优化黏滞阻尼器的布设位置。结果表明,黏滞阻尼器在保证不增加结构刚度的基础上,通过提供附加阻尼,能有效协助结构耗散地震输入的能量,降低了结构的动力响应,起到了很好的减震效果。同时,在考虑黏滞阻尼器的布设位置时,应根据结构的实际动力响应和变形特性综合确定,并且考虑结构的功能需求以获得最佳的减震效果。     

基于风振舒适度的北京奥林匹克塔黏滞阻尼减振性能研究

以北京奥林匹克塔为工程背景,对其展开以舒适度为控制指标的黏滞阻尼减振性能研究。根据该多塔高耸结构的特点设计了连接桁架加腋的结构方案和不加腋的结构方案,比较分析两者之间动力特性的变化。并在连接桁架不加腋结构方案的基础上引入黏滞流体阻尼器(viscous fluid damper, VFD),对阻尼器的安装位置、装置数量等进行优化设计,形成了结构黏滞阻尼减振方案。利用风洞试验结果生成的三维风场,开展了连接桁架加腋方案、连接桁架不加腋方案和黏滞阻尼减振方案的风振响应分析,并从响应的空间分布、受风向角影响规律、时频域特性和阻尼器输出特性等方面进行分析。结果表明：相对于连接桁架不加腋方案,无论是连接桁架加腋方案还是黏滞阻尼减振方案,结构的加速度峰值响应均有不同程度的减小,其中黏滞阻尼减振方案最大衰减可达30.28%。     

某超大高宽比超高层建筑风振控制研究

根据某超大高宽比超高层住宅建筑提高风振舒适度的需求,拟采用黏滞阻尼器来减小风致振动,通过对阻尼器沿竖向不同部位布置的多个方案进行风振及小震时程分析,对比研究了不同布置方案分别对结构顶点加速度、层间位移角及基底剪力的减振效果,结果表明合理布置的黏滞阻尼器可有效降低顶点风振加速度,也可有效降低小震作用下的基底剪力与层间位移角。     

消能减震伸臂桁架在超高层结构中的风振控制研究

随着建筑物高度的增加,框架-核心筒-伸臂结构体系的应用越来越多。同时,多道伸臂桁架的布置在超高层结构中越来越普遍,较柔的超高层结构的自振频率接近脉动风的频率,风振下结构的加速度较大,易引起舒适度问题。针对某带多道伸臂桁架的超高层建筑,提出在伸臂桁架与外框架间布置黏滞阻尼器的方法,即采用带黏滞阻尼器的消能减震伸臂桁架,来控制结构在风振下过大的加速度响应,重点分析其抗风性能及在不同高度的伸臂桁架中布置黏滞阻尼器的减振效率。     

高层建筑基于风速风向联合概率分布作用的风致响应可靠度分析

为研究高层建筑多风向风致加速度满足人体舒适度要求的可靠度,推导了以结构顶部加速度响应均方根值表征的近似解析表达式,建立了风速风向联合分布的概率模型。并以广州西塔高层建筑为算例,结合其工程气象分析及风洞试验等相关资料,通过随机振动理论和曲线拟合方法,得到其在主要风向角下风致顶部加速度响应均方根值与10 m高度平均风速的拟合表达式。在此基础上,考虑平均风速服从Weibull分布,阻尼比服从正态分布条件下,基于条件概率,采用验算点法对此高层建筑在考虑风速风向联合概率分布情况下,满足重现期10年的顶部风致加速度响应(舒适度)要求的可靠度进行了分析,表明结构顶部重现期10年风致加速度失效概率在各方向有明显差别,说明考虑风速风向联合分布的风致结构舒适度失效概率计算的必要性。采用本文的验算点法对本算例高层建筑的可靠度分析,结果表明其对应重现期10年的考虑风速风向联合概率分布情况下满足舒适度要求的可靠度值达99.98%。     

基于能量和控制效果指标的黏滞阻尼器优化设计

提出以能量和控制效果指标为目标函数的黏滞阻尼器优化设计方法。基于黏滞阻尼器参数对其滞回曲线的影响,在分别以加速度控制效果指标和能量为目标函数的情况下,采用遗传算法对黏滞阻尼器进行了布置及参数的同步优化,在综合考虑了位移控制效果指标、加速度控制效果指标及能量的情况下,再次对黏滞阻尼器进行了优化设计,将三种黏滞阻尼器优化设计结果与传统设计结果进行了比较,并分析了四种阻尼器设计结果对地震的敏感性。研究表明:考虑能量的黏滞阻尼器优化设计是有效的,在目标函数中引入能量可以减小设计结果对地震波的敏感性。     

深圳恒裕金融中心液体黏滞阻尼器抗风性能验证项目及测试案例

随着建筑工程在高度上的迅速发展,风致振动带来的影响日益普遍,高层建筑的抗风问题已在工程界受到极大重视。如今人们对建筑结构提出的要求也已经不仅仅局限于满足安全性目标,而会进一步考虑其舒适度与宜居性。许多工程实例证明,采用液体黏滞阻尼器进行高层建筑的风振控制是一种提高人们舒适度的有效方法。基于此,从结构抗风切入,介绍了抗风工程应进行的几个重要的测试项目,并以深圳恒裕金融中心项目所用液体黏滞阻尼器的测试报告为范本,介绍了液体黏滞阻尼器抗风性能测试的内容并给出了测试结果。最后指出进行阻尼器测试的重要性与紧迫性,并从规范制定,到阻尼器制造、测试以及监管等诸方面对各有关部门提出建议,以求改进现阶段国内阻尼器行业的种种乱象。     

基于遗传算法的摩擦摆TMD系统参数优化分析

为使高层建筑顶部设置双向摩擦摆(FPS-TMD)系统的风振控制效果达到最优,本文采用自适应基因遗传算法,对此类被动控制系统的滑道摩擦系数和两个方向滑道半径的优化设计进行相关研究。并以广州新电视塔为实例,以顶部有无设置FPS-TMD系统的主体结构顶部风致位移或风致加速度均方根之比最小为风振控制优化设计的目标函数,采用自适应基因遗传算法,利用精英保存策略、自适应交叉和变异算子,以及自适应罚函数处理主体结构的风致层间位移约束、顶层风致位移和顶层风致加速度响应约束条件。优化分析结果表明,采用本文的自适应基因遗传算法,可以有效地对顶部带双向摩擦摆TMD系统的高层建筑,进行风振控制条件下的系统参数优化分析。     

偏心结构黏滞阻尼器的空间位置优化

提出了一种基于遗传算法的黏滞阻尼器空间位置优化方法,运用GATBX遗传算法工具箱编制遗传优化程序,通过编制空间三维协同弹塑性动力时程反应分析程序来对结构上设置多个黏滞阻尼器的空间位置进行优化,以控制偏心结构在多维地震作用下的扭转联耦反应。选用两种目标函数,以一个6层的偏心结构为算例,比较阻尼器的均匀布置和优化布置的结构动力响应。优化布置阻尼器可以更有效地减小最大层间位移角,使层变形趋向于均匀,采用遗传算法计算所得结构控制效果较好。     

基于GA的高层结构VED阻尼器优化布置

本文对安装有粘弹性阻尼器的高层建筑结构进行了强震作用下的动力时程分析,基于Newmark-β法获得结构的振动响应。在阻尼器数量一定的情况下,为寻求最佳的布置方案,以结构最大层间位移角和楼层最大加速度的线性组合构造了目标函数,采用GA算法对阻尼器的布置位置进行了优化。数值试验表明了这一优化布置方案的可行性和有效性。     

Serviceability‐based damping optimization of randomly wind‐excited high‐rise buildings

Fluid viscous dampers are proved to be effective for reducing the response of high‐rise buildings subjected to wind excitations so as to enhance structural habitability, which serves as a critical performance in serviceability design. High‐rise buildings attached with fluid viscous dampers, however, exhibit nonlinearity and even act as stiff systems in most cases of wind‐induced vibration mitigation. The traditional equivalent linearization methods employed in practices often fail to obtain an accurate solution. Equivalent linearization methods, including the energy‐dissipation equivalent linearization method and the statistical linearization technique, are first studied and validated in this paper by the backward difference formula, which was verified to be of high accuracy through the nonlinear dynamic analysis. The damping optimization for habitability control is then proceeded. Two families of serviceability criteria, the minimization of standard deviation of roof acceleration employed in traditional habitability analysis and the minimization of failure probability of roof acceleration proposed in the present study, are addressed. For the logical treatment of randomness inherent in wind excitations and its influence upon structural reliability, the probability density evolution method is employed. Numerical results reveal that the criterion of minimizing failure probability of roof acceleration has better performance in habitability enhancement.     

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.     

Distribution of strong earthquake input energy in tall buildings equipped with damped outriggers

The seismic design of optimal damped outrigger structures relies on the assumption that most of the input energy will be absorbed by the dampers, whilst the rest of the structure remains elastic. When subjected to strong earthquakes, nevertheless, the building structure may exhibit plastic hinges before the dampers begin to work. In order to determine to which extent the use of viscously damped outriggers would avoid damage, both the host structure's hysteretic behaviour and the dampers' performance need to be evaluated in parallel. This article provides a parametric study on the factors that influence the distribution of seismic energy in tall buildings equipped with damped outriggers: First, the influence of outrigger's location, damping coefficients, and rigidity ratios core‐to‐outrigger and core‐to‐column in the seismic performance of a 60‐story building with conventional and with damped outriggers is studied. In parallel, nonlinear behaviour of the outrigger with and without viscous dampers is examined under small, moderate, strong, and severe long‐period earthquakes to assess the hysteretic energy distribution through the core and outriggers. The results show that, as the ground motion becomes stronger, viscous dampers effectively reduce the potential of damage in the structure if compared to conventional outriggers. However, the use of dampers cannot entirely prevent damage under critical excitations.     

Optimization layout of viscous dampers and its application in retrofitting of a high-rise steel structure

阻尼器优化布置是结构减震设计过程中的重要环节，通常需要通过多次动力响应计算来完成。为此，提出了一种通过结构静力分析确定阻尼器合理布置位置的方法，并能够快速计算出优化方案的附加阻尼比。将该方法应用于一栋位于日本东京都新宿区29层钢结构建筑的减震加固设计中，分析了该建筑的强震观测系统在日本“311地震”中采集到的部分楼层加速度时程数据，并基于分析结果验证了所建立的非线性数值分析模型的可靠性。采用所提方法对结构进行减震加固，得到双向共64个阻尼器的优化布置方案及其附加阻尼比，并通过动力方法对结果进行了验证。同时针对长周期及长持时特性的地震波，对减震结构进行动力弹塑性时程分析，评估其抗震性能。分析结果表明：减震优化方案的减震效果明显，结构整体地震反应和构件损伤较非减震方案都大大减小；减震优化方案有效改善了高层钢结构楼层变形不均匀的情况，层间位移角均满足小于1/100的性能要求；通过减震优化后大部分钢支撑和钢梁的塑性率都降低至小于1。     

黏滞阻尼器的优化布置及其在高层钢结构加固中的应用

阻尼器优化布置是结构减震设计过程中的重要环节,通常需要通过多次动力响应计算来完成。为此,提出了一种通过结构静力分析确定阻尼器合理布置位置的方法,并能够快速计算出优化方案的附加阻尼比。将该方法应用于一栋位于日本东京都新宿区29层钢结构建筑的减震加固设计中,分析了该建筑的强震观测系统在日本“311地震”中采集到的部分楼层加速度时程数据,并基于分析结果验证了所建立的非线性数值分析模型的可靠性。采用所提方法对结构进行减震加固,得到双向共64个阻尼器的优化布置方案及其附加阻尼比,并通过动力方法对结果进行了验证。同时针对长周期及长持时特性的地震波,对减震结构进行动力弹塑性时程分析,评估其抗震性能。分析结果表明：减震优化方案的减震效果明显,结构整体地震反应和构件损伤较非减震方案都大大减小;减震优化方案有效改善了高层钢结构楼层变形不均匀的情况,层间位移角均满足小于1/100的性能要求;通过减震优化后大部分钢支撑和钢梁的塑性率都降低至小于1。     

Wind-induced vibration control of Hefei TV tower with fluid viscous damper

The Hefei TV tower is taken as an analytical case to examine the control method with a fluid viscous damper under wind load fluctuation. Firstly, according to the random vibration theory, the effect of fluctuating wind on the tower can be modeled as a 19-dimensional correlated random process, and the wind-induced vibration analysis of the tower subjected to dynamic wind load was further obtained. On the basis of the others’ works, a bi-model dynamic model is proposed. Finally, a dynamic model is proposed to study the wind-induced vibration control analysis using viscous fluid dampers, and the optimal damping coefficient is obtained regarding the wind-induced response of the upper turret as optimization objectives. Analysis results show that the maximum peak response of the tower under dynamic wind load is far beyond the allowable range of the code. The wind-induced responses and the wind vibration input energy of the tower are decreased greatly by using a fluid viscous damper, and the peak acceleration responses of the upper turret is reduced by 43.4%.     

单重和多重调谐质量惯容阻尼器控制连体超高层建筑风振响应比较研究

连体超高层建筑因存在强烈的气动干扰,在强风下可能会出现大幅相对振动,调谐质量惯容阻尼器(TMDI)是一种振动控制装置,其惯容器两端的相对加速度较大时,TMDI振动控制效果较好.结合两者各自的特点提出了多重调谐质量惯容阻尼器(MTMDI)控制连体超高层建筑的风振响应,两个TMDI分别控制两栋建筑各自的一阶自振频率.首先建...     

调频减振系统和黏滞阻尼系统在超高层结构中风振控制性能的对比研究

超高层建筑中常用的风振控制措施主要包括调频减振系统和黏滞阻尼系统。系统地阐述了两种方案的基本原理、工程适用性以及参数取值,并结合实际项目较为全面地对比了其抗风性能。虽然调频减振系统在建筑功能的适应度上和施工可实施性上都存在一定的不足,但作为结构风振控制措施仍不失为一种可取方案。黏滞阻尼系统不但可以提升结构在风荷载下的舒适度,还能提升结构在风荷载和地震作用下的刚度和强度,适应了结构应对不同抗风设防水准的性能需求。结合高效的连接形式,黏滞阻尼系统是一种适用于高层、超高层建筑抗风的高性能且经济的减振控制措施。     

Optimal parameters for tall buildings with a single viscously damped outrigger considering earthquake and wind loads

Tall buildings suffer from low inherent damping and high flexibility. Therefore, a core-outrigger system is often used to stiffen such buildings. A modified form, known as the damped outrigger system, wherein vertically oriented dampers are installed between outriggers and perimeter columns, has been recently developed to supplement the damping. This paper studies the efficacy of a viscously damped outrigger system through dynamic analysis of a 60-story tall building subjected to nonconcurrent earthquake and wind excitations. Two ground motion sets (100 accelerograms) are used for the former and wind tunnel test data for the latter. Effects of three building parameters, namely, (i) the core-to-column stiffness ratio, (ii) the outrigger location, and (iii) the damper size, on the dynamic characteristics and seismic and wind responses are evaluated. Effects of damper nonlinearity on seismic and wind responses are also investigated considering energy-equivalent nonlinear viscous dampers. Finally, the optimum values of these parameters are determined. For example, the optimum outrigger location is found to be between $0.6H$ to $0.9H$, where $H$ is the height of the building. The results also show that the damped outrigger system significantly outperforms the conventional one for seismic excitation, and it is very effective in reducing the wind-induced floor accelerations, provided the parameters are chosen appropriately.