用TLD减小电视塔动力反应的振动台试验研究

本文介绍了用环形调频液体阻尼器（ＴＬＤ）减小电视塔动力反应的模型结构振动台试验研究。结果表明，ＴＬＤ能有效地减小第一振型的位移共振反应；在地震激励下，ＴＬＤ减小峰值反应的效果不十分显著；但地震停止后，ＴＬＤ使模型结构的自由振动迅速衰减。     

结构控制中圆柱形浅水TLD的研究

本文采用有限元方法对圆柱形浅水ＴＬＤ装置中液体在水平激励下的运动状态进行了分析。给出了相应的数值计算模型与减振力的计算公式。     

局部双层网壳结构的减震设计分析

对增设粘滞阻尼器的局部双层网壳结构进行减振分析,探讨了阻尼器位置、数量、阻尼系数等不同参数对局部双层网壳结构减振性能的影响,分析了不同参数阻尼器的减振效果.计算分析表明:结构阻尼单元的阻尼系数越大,结构的减振效果越好;设置的阻尼器数量越多,结构减振效果越好;对于局部双层球壳结构,斜向设置粘滞阻尼器的效果最佳.     

半柔性悬挂减振结构体系地震反应分析

针对一种新型高层建筑半柔性悬挂结构体系提出阻尼减振控制的方案。首先,阐述了结构体系构建方案及优越性;其次,以主体结构的时程响应最大值最小为控制目标,对粘滞流体阻尼器的阻尼系数进行优化分析;最后,基于最优的阻尼器参数,对半柔性悬挂减振结构与普通悬挂抗震结构进行了时程对比分析。结果表明:半柔性悬挂减振结构能够有效地消弱结构的峰值响应;存在最优的阻尼系数使得主体结构的顶点位移和基底剪力动力响应最小;悬挂楼段保持较小层间位移,有效发挥了各层阻尼器的效率,保护了非结构构件。     

无约束阻尼在输电线塔中的应用

提出一种无约束阻尼用于输电线塔阻尼减振的方案。从输电线塔重要性角度提出振动控制阻尼减振的必要性；合理选择输电线塔适宜的阻尼布置方式和阻尼类型，提出无约束阻尼在输电线塔中的布置方式，使竖向主要构件成为阻尼比很大的复合耗能构件。本文选取一钢塔架案例，进行强风作用下耗能减振时程分析；参考文献中无约束阻尼的计算方法。计算结果显示，无约束阻尼对塔架位移有较好减振效果，对塔架加速度减振效果非常明显。无约束阻尼适用于输电线塔的阻尼减振，提高输电线塔安全性。     

巨型框架悬挂减振结构的参数分析

基于有限元软件ABAQUS分析了巨型框架悬挂减振结构中阻尼器的阻尼系数和刚度系数的变化对结构地震响应的影响,给出了参数分析的目标函数和约束条件,结果表明:在最优的阻尼器的阻尼系数使综合减振系数最大,此时悬挂楼层的位移角也能得到有效控制,且可以通过增加刚度系数来减小层间位移角;存在最优的刚度系数使综合减振系数最大,而此时悬挂楼层层间位移角可能不满足要求,这可以通过增加阻尼系数来保证。     

基于风洞试验的变阻尼质量调谐阻尼器景观塔的减振分析

基于风洞试验得到的各结构层风荷载时程，采用ABAQUS软件对景观塔无控结构和有控结构进行10,50,100 a重现期风作用下的风振响应分析，得到了质量调谐阻尼器(TMD)在不同重现期风荷载作用下的减振效果。计算结果表明：两级变阻尼TMD能有效减小风荷载作用下结构的响应，减振效率随着楼层的增高而增大；风荷载作用下TMD均未超出最大行程，10 a重现期风作用下处于一级阻尼；50、100 a重现期风作用下二级阻尼发挥作用；设置TMD能有效提高结构舒适度，TMD对加速度控制的效率高于位移控制；TMD作为一种有效的减振控制装置，适用于有限位需求的高耸结构风振设计。     

一种颗粒阻尼装置的等效减振特性研究

颗粒阻尼是通过在有限封闭空间内填充颗粒,利用颗粒之间的碰撞摩擦等能量消耗作用进行减振的。由于颗粒材料振动响应的高度非线性,在理论上难以直接建立其减振力学机制表达。本文通过动力模型试验和数值模拟建立了一种等效阻尼模型来表征颗粒的耗能特性。首先设计了高精度激光振动位移检测试验平台,对颗粒阻尼结构模型的振动状态进行了位移时程测量,对比分析了不同颗粒阻尼装置的减振规律;在试验基础上,采用颗粒接触有限元模型对颗粒阻尼装置的工作过程进行了数值模拟,通过与试验结果比对验证数值模型及参数选取的有效性;最后将数值模型中的颗粒系统基于开尔文模型表达颗粒阻尼装置的减振效应。物理试验研究与数值模拟结果表明,不同颗粒材料和粒径的颗粒阻尼装置有不同的减振效果;参数合理的等效阻尼模型能有效表达颗粒阻尼装置的减振效果。     

带有液体粘滞阻尼器的超高层建筑抗风设计及风振响应分析

超高层建筑遮挡物较少,在风荷载作用下,结构顶部强烈的风振加速度会引起人的不适。通过在超高层结构合理布置液体粘滞阻尼器增加结构阻尼比,从而有效控制结构风振响应,达到减振目的。以珠海某超高层工程实例为背景,采用风洞试验计算脉动风荷载时程,在最不利风向角风荷载时程作用下,对比分析了阻尼器不同楼层布置位置、不同平面布置位置、不同阻尼弹簧刚度及不同阻尼参数下的减振效果,选出最合理阻尼器布置方式,结构顶层风振加速度得到有效控制,减振效果明显。     

简谐荷载作用下分数导数型粘弹性两自由度阻尼系统受迫振动分析

在简谐荷载的作用下,建立了分数导数型粘弹性两自由度阻尼系统的运动方程,利用分数导数的性质,得到了系统位移的解析解和振幅比的表达式;分析了各个结构参数对系统振幅比和振动特性的影响,为结构的粘弹性阻尼减振和被动控制提供依据。     

Numerical studies on the application of tuned liquid dampers with screens to control seismic response of structures

Tuned liquid damper (TLD) systems are nowadays increasingly being used as one of the economical and effective passive vibration absorbers. A TLD system consists of a water tank having the fundamental sloshing fluid frequency tuned to the frequency near to the natural frequency of structure. This research focuses on modelling tall buildings equipped with TLDs having inside screens subjected to strong ground motions. Strong excitation can cause wave‐breaking phenomenon and makes turbulent in shallow rectangular tanks which could also contribute to the additional damping due to TLDs. On the other hand, wire screens placed inside a liquid tank can play an important role in reducing the structural response due to increasing the inherent damping of the structure. Based on equalizing dissipated energies, a TLD equipped with internal screens can be modelled by equivalent amplitude‐dependent tuned mass damper (TMD). In this study, adopting this simple method, equations of motion for shear‐type buildings equipped with nonlinear amplitude‐dependent TMDs were developed. A complex modal analysis procedure was used to solve the governing equations. Coupling of TMD properties and structural response was solved with iteration on structural response and updating TMD properties. Performing a set of parametric studies on three proposed tall structures equipped with TLD subjected to different ground excitations showed that if the TLD is tuned to a frequency close to the natural frequency of the structure considering hardening behaviour of TLD, it could significantly reduce the seismic response (displacements and base shears) of the structures. Copyright © 2009 John Wiley & Sons, Ltd.     

A hybrid structural control system using a tuned liquid damper to reduce the wind induced motion of a base isolated structure

This study investigates the use of a tuned liquid damper (TLD) as a cost effective method to reduce the wind induced vibrations of base isolated structures. The TLD is modelled as an equivalent linearized mechanical system in which the damping and natural frequency of the sloshing fluid are amplitude dependent quantities. The base isolated structure is represented using a modified form of the linearized Bouc-Wen model, which enables the behaviour of Stable Unbonded Fibre Reinforced Elastomeric Isolators (SU-FREIs) to be described. The TLD and base isolated structure are combined to form a system of coupled ordinary differential equations, the solution to which produces frequency response curves for the structure and TLD. A preliminary TLD design procedure is presented which allows the proper tank dimensions and damping screen properties to be established. The equivalent linearized mechanical model is validated using time simulations which account for the nonlinear behaviour of the structure and fluid. The models are found to be in excellent agreement. A TLD is found to be an effective means to control the wind induced vibration of a base isolated structure.     

Earthquake vibration control of structures using hybrid mass liquid damper

A tuned liquid damper (TLD) is a passive vibration control device consisting of a rigid tank filled with water that relies on the sloshing of water inside it to dissipate energy. In a standard TLD configuration the TLD is connected rigidly to the top of the building structure. Earlier research has shown that the TLD is more effective when its base acceleration amplitude is larger, as it dissipates more energy through increased sloshing. This characteristic has been utilized to design this alternate TLD configuration. In this alternate TLD configuration, the TLD is rigidly attached to a secondary mass that is attached to the primary structure through a spring system. This alternate configuration is, thus, defined as a hybrid mass liquid damper (HMLD). For particular values of the secondary spring’s flexibility, the motion of the secondary structure is in phase with that of the primary structure and the TLD base is subjected to a large amplitude acceleration that increases its effectiveness. It should be noted that when the secondary spring is rigid, the alternate and standard TLD configurations are identical for very small values of the secondary mass. It is seen that, for a given structure with HMLD there exists an optimum value of the secondary spring’s stiffness for which the HMLD effectiveness is maximum. An optimally designed HMLD configuration is shown to be more effective as a control device than the standard TLD configuration for both harmonic and broad-band earthquake motions.     

TLD减小钢桥塔涡激振动的原理及应用研究

讨论了TLD（Tuned Liquid Damper）的减振机理，并用解析形式给出了TLD对结构控制的减振力，求出了TLD与结构相互作用时结构的位移响应，推导了结构安装TLD后结构的等效阻尼比，给出了结构的减振效率，验证了TLD减振效果非常好，可以保证桥塔建设过程中的施工安全。     

浅埋地下结构底板在竖向地震作用下动力响应

本文研究了地下结构底板在地震竖向分量作用下的动力响应。利用结构动力学和弹性力学的理论,得到底板的运动微分方程,根据边界条件确定底板在的特征频率和振型。针对输入的地震竖向分量的形式,采用分离变量法求解了强迫振动方程.计算时取前三阶振型,采用振型叠加法得到底板的相对位移和绝对位移,并进而求得底板的弯矩,利用求得的弯矩,可以求解底板的受力情况。通过底板的受力情况,可以直观地对地下结构底板进行评价分析,并且推进了地下结构底板抗震理论的研究和发展。     

Shallow cylindrical tuned liquid damper for vibration control of high‐rise structures

A new simplified model for the application of a shallow cylindrical tuned liquid damper (TLD) in structural vibration control is presented in this paper. The dynamic properties of a shallow liquid in cylindrical containers subjected to forced horizontal oscillation are analysed directly from the continuity and momentum equations of fluids. Following some practical assumptions, the nonlinear partial differential equations describing the wave movement of a shallow liquid in cylindrical containers is established and a numerical procedure for the solution of these equations is proposed using the finite element method. The formula for determining the control force provided by the shallow cylindrical TLD is presented and the effect of several parameters on the control efficiency of a shallow cylindrical TLD controlled structure under wind action is investigated. Copyright © 2002 John Wiley & Sons, Ltd.     

Numerical Modeling of Dynamic Behavior of Annular Tuned Liquid Dampers for Applications in Wind Towers

Abstract: In this study, the performance of annular liquid tanks as a tuned liquid damper (TLD) in mitigating the vibration of wind turbines was investigated using a numerical model. A proposed hybrid wind tower model composed of a concrete shaft and a steel mast with a height of 150 m was simulated using a single‐degree‐of‐freedom system. The structural domain including the tank wall and a rigid mass was modeled using finite element method, while the fluid domain was simulated by finite volume method using CFX software. A parametric study was carried out to investigate the behavior of annular TLD under harmonic loads for different mass and frequency ratios as well as displacement amplitudes. The damping characteristics of the annular TLD model were derived by comparing the numerical results with an equivalent linear model. In addition, the effectiveness of annular TLD was estimated by comparing the numerically calculated damping ratios with those corresponding to the optimum damping ratio values derived for a particular mass ratio based on the concept of tuned mass damper. It was found that that the annular TLD is effective when the amplitude of excitation is small. Moreover, the response of TLD in terms of nonlinear free surface sloshing and the energy dissipated by the system was discussed. Finally, the effectiveness of annular TLD in reducing the structural response of wind turbine towers under random vibrations was evaluated and discussed.     

Liquid damper for suppressing horizontal and vertical motions—parametric study

The new type of passive tuned liquid damper (TLD), which relies on the motion of liquid inside a movable rectangular tank with two degrees of freedom (horizontal displacement and rotation), is investigated, including the influence of a vessel's horizontal motion and rotation on the damping of the vertical and horizontal vibrations of footbridges. Experimental solution consists in the determination of the magnitude of the excitation force of the shaking table required under resonance during the excitation of the vessel.     

Application of spherical tuned liquid damper in vibration control of wind turbine due to earthquake excitations

A spherical tuned liquid damper (TLD) is proposed as a cost‐effective method to reduce the earthquake‐induced vibration of wind turbines. A 1/20‐scale test model was designed to investigate its performance of controlling the structural vibration. A series of free and forced vibration experiments with different water depths in hemispherical containers were performed on the shaking table. Three measured ground acceleration‐time histories, including El Centro NS, El Centro EW and Tianjin EW, were selected to verify the effectiveness of spherical TLD in suppressing the earthquake‐induced vibration. The experimental results showed that the spherical TLD could effectively improve the damping capacity of the test model. The standard deviation of the dynamic response could be effectively reduced when the excitation frequency was approximately equal to its fundamental frequency. The liquid sloshing motion in containers was characterized by a highly nonlinear and complex nature. The effectiveness of spherical TLDs does not increase linearly as the mass of water in containers and is influenced greatly by the frequency components of earthquake excitations. For El Centro EW excitation, the standard deviations of the dynamic responses could be reduced more than 40% when the liquid mass was about 2% of the generalized mass. Copyright © 2015 John Wiley & Sons, Ltd.     

高层建筑结构的风振阻尼控制分析与设计方法

本文首先分析了阻尼比对结构风振反应的控制效果,重点讨论了阻尼比对风振脉动增大系数的减小效果和具体计算方法,给出了便于工程实际应用的阻尼比为10%～30%的风振脉动增大系数随基本风压和结构基本周期变化的计算图表。结果表明,结构阻尼比增大,风振脉动增大系数明显减小。其次,分析了结构耗能减振系统的附加阻尼特性,给出了调频质量阻尼器(TMD)、调频液体阻尼器(TLD)和速度线性相关型耗能器附加给结构阻尼比的实用计算公式。最后给出了100层钢结构分别设置TMD和线性粘滞阻尼器的风振控制分析和设计实例。实例结果表明,两种被动阻尼控制系统对结构最大位移和最大加速度控制效果相同,可以达到40%～55%,同时说明了本文提出的方法可以方便地用于大型结构的风振阻尼控制分析和设计。