磁流变式调谐液柱阻尼器对结构风致抖振控制研究

磁流变式调谐液柱阻尼器(MR-TLCD)是由调谐液柱阻尼器(TLCD)和磁流变液阻尼器(MRD)组成的新型半主动控制装置.建立了含有半主动控制力项的MR-TLCD力学模型以及MR-TLCD与单自由结构耦合运动方程,等效线性化处理了MR-TLCD力学方程中的非线性阻尼项.采用谱分析方法研究了MR-TLCD对单自由结构风致抖振情况下控制效果.研究结果表明,在质量比和频率比一定的情况下,MR-TLCD能够通过只改变外接电源进而改变MR-TLCD阻尼力即可实现良好的优化减振性能.且加速度控制效果优于位移控制效果.     

磁流变式调谐液柱阻尼器的离复位控制

提出了抑制水平振动的磁流变式调谐液柱阻尼器(MR-TLCD)模型,建立了单自由度结构——MR-TLCD的耦合运动方程。从系统动力方程出发,根据离复位控制策略,确定了MR-TLCD与单自由度结构相互作用过程中的合理阻尼大小。数值计算中,利用谐波叠加法模拟风荷载作用于该系统,并通过调节MR-TLCD的电压进行实时控制。仿真结果说明了在离复位控制策略下,MR-TLCD用于结构风振控制的合理性和有效性,是理想的半主动控制装置。     

磁流变式调谐液柱阻尼器对地震作用的控制研究

磁流变式调谐液柱阻尼器(MR-TLCD)是在调谐液柱阻尼器(TLCD)基础上发展的一种新型减振装置.建立了MR-TLCD数学模型,采用了等效阻尼线性化处理方法,分析了地震作用下对不同质量比、频率比以及可调控制剪切力等参数变化下对减振效果的影响.结果证明,磁流变式调谐液柱阻尼器对地震作用下单自由振动控制具有良好的控制效果.     

半主动变刚度TLCD减振控制的研究

为改进被动式调频TLCD的减振特性,提出了半主动变刚度TLCD减振系统,基本原理是将调频TLCD的弹簧设置成可调谐状态,在振动过程中,根据减振系统的需要适时调整调频弹簧的开关状态。减振系统的刚度由两部分组成,一部分是液体振动的恢复力,另一部分由变刚度装置的弹簧提供。由Lagrange方程建立起半主动变刚度TLCD的运动方程,以一个单自由度结构体系为算例,分析了可变刚度对系统控制性能的影响。外荷载频率与结构的频率比取不同值,比较了被动TLCD、半主动变阻尼TLCD和半主动变刚度TLCD的减振频带。考虑TLCD的频率和结构的实际频率之间存在一定的误差时,研究了半主动变刚度TLCD的减振性能。最后,通过一个五层结构的算例,分别在谐波和地震波作用下,验证了半主动变刚度TLCD对多自由度结构体系的减振特性。研究结果表明,半主动变刚度TLCD具有更宽的减振频带,在TLCD的频率和结构振动的频率存在误差时,仍能保持较好的减振效果。     

改进的Bang-Bang控制算法的理论与试验研究

将电压的切换时间作为可调参数,提出了基于位移反馈的改进的Bang-Bang控制算法。建立了磁流变阻尼器对拉索减振的半主动控制的有限元模型以及基于dSPACE、MATLAB/Simulink和磁流变阻尼器等工具的半主动控制试验平台,从有限元数值仿真和试验实测两方面分析了改进的Bang-Bang控制算法和最优被动控制对拉索减振效果的影响。理论计算和试验实测结果都表明改进的Bang-Bang控制对拉索的减振效果优于最优被动控制,同样优于经典的Bang-Bang控制算法;半主动控制时阻尼器输入电压的切换时间对拉索系统的减振效果至关重要。     

磁流变阻尼器系统的非线性动力学分析

以单自由度非线性磁流变阻尼器系统为研究对象,通过变换磁流变阻尼器的外加电压,对系统实施半主动开-关控制。在分析系统运动特征基础上,给出了系统的运动微分方程,利用平均法进行分析求解。根据奇异性理论得到系统基的普适开折以及特例情况下的转迁集。并将磁流变阻尼器应用到转向架横向动力系统的振动控制中,分析了系统参数对幅-频特征曲线以及稳定性的影响     

旁置孔隙阀式磁流变阻尼器阻尼力解析解

基于Bingham模型推导了磁流变液流经孔隙阀时流体的运动方程,孔隙阀式磁流变阻尼器阻尼力与阻尼器的结构参数、磁流变液的性能参数的关系为四次代数方程,应用代数方程理论得到了阻尼力的解析解,分析了磁流变液的黏度、屈服强度、磁流变阻尼器结构参数对阻尼性能的影响,本文的研究可用于指导阻尼器设计。     

基于磁流变阻尼器的结构模糊半主动控制实验研究

基于磁流变阻尼器的结构半主动控制兼有被动和主动控制的优点,近年来受到了广泛的关注,但设计与之相适应的控制系统仍是一项具有挑战性的工作。本文针对多输入多输出结构-阻尼器系统,提出了一种基于遗传算法的模糊控制器设计方法。由遗传算法自适应优化生成模糊控制规则,建立从加速度响应到磁流变阻尼器控制电压之间的关系,对结构进行半主动控制。通过两个结构振动控制实验,证明了该方法的有效性。     

具有参数不确定性的车辆座椅悬架H∞输出反馈半主动控制

针对座椅悬架系统的参数不确定性和位移测量难题,基于线性矩阵不等式和H∞最优控制理论,建立了座椅悬架系统的参数不确定性H∞输出反馈控制器。控制器利用估计的状态采用鲁棒控制策略计算期望控制力。磁流变阻尼器的控制电压在满足半主动和极值约束条件下,比较期望控制力与当前阻尼力的大小,应用开关控制算法进行调整,使得磁流变阻尼器产生跟踪期望控制力的阻尼力。数值仿真结果证明,该控制器在仅利用座椅架的加速度作为测量输出进行状态估计,以及在座椅悬架系统具有参数不确定性的情况下,仍能有效地对座椅外部激励进行隔振,改善驾驶员的乘坐舒适性。     

磁流变阻尼器模型及悬架半主动控制研究

分析了磁流变阻尼器的多项式模型,并将其应用于汽车悬架的半主动控制.作为比较,对两种被动控制和一种半主动控制策略进行研究.1/4车辆模型在C级路面激励下的数值仿真结果表明,基于多项式模型磁流变阻尼器的半主动控制较被动控制有明显效果,且多项式模型对磁流变阻尼器的阻尼力描述准确,涉及参数简单,易于适时调整,因此具有良好的应用前景.     

Stochastic optimal control of wind-excited tall buildings using semi-active MR-TLCDs

A new semi-active control device, magneto-rheological tuned liquid column damper (MR-TLCD), has been devised recently by the authors for mitigation of wind-induced vibration response of tall building structures. The developed device combines the benefits of magneto-rheological smart materials and tuned liquid column dampers. In this paper, real-time semi-active vibration control of tall building structures incorporating nonlinear MR-TLCDs under random wind excitation is studied by means of the statistical linearization method and the optimal linear quadratic (LQ) control strategy. The equations of motion of a tall building structure subjected to random wind loading and controlled by using MR-TLCDs at the top floor are first derived and represented in modal coordinate. After linearizing the uncontrollable part of MR-TLCD damping force and incorporating it with structural components, the classical linear quadratic (LQ) control strategy is applied to the linearized structural system to determine optimal control force of the MR-TLCDs. Clipping treatment is performed to ensure the commanded control force implementable by the MR-TLCDs. Wind-excited response of the semi-actively controlled structural system is evaluated by using the frequency-response function and then compared with that of the passively controlled structure to determine the control efficacy. A case study of a 50-story building structure is conducted to illustrate excellent control efficacy of the proposed semi-active MR-TLCD control system.     

TLCD-结构转化为TMD-结构减振控制的研究

该文针对平面对称结构和不对称结构,比较TLCD-结构体系和TMD-结构体系的耦联微分方程,得到TLCD-主结构与TMD-主结构质量比、频率比、主结构自振频率和主结构阻尼等,由此可将TLCD-结构体系转化为TMD-结构体系,利用DenHartog公式对TLCD阻尼比和频率比参数优化,并用有限元软件来对复杂结构减振控制进行数值计算。通过单层平面不对称结构和20层Bechmark模型放置单个或多个TLCD,用DenHartog公式求得TLCD参数,并用SAP2000进行结构分析,与MATLAB结果进行比较来验证该方法的合理性和可行性。     

动调频液柱阻尼器基于遗传算法的LQR控制优化设计

ATLCD由调频液柱阻尼器(Tuned Liquid Column Damper,TLCD)发展而来,在TLCD液柱端部连接气压控制箱,通过引入控制气压对结构实施主动控制。采用被动TLCD优化设计方法设计阻尼比及频率比,采用LQR算法确定ATLCD系统的主动控制力,并对LQR算法中权矩阵采用遗传算法进行优化。以一五层钢框架结构为例,顶层装ATLCD用LQR算法进行主动控制,加载El-Centro地震波进行时程响应分析,比较无控结构及被、主动控制结构的时程响应结果表明,采用ATLCD的减振效果明显优于采用被动装置。     

Hybrid control of irregular steel highrise building structures under seismic excitations

Control of irregular highrise building structures under various seismic excitations is investigated using a hybrid control system consisting of a passive supplementary damping system and a semi‐active tuned liquid column damper (TLCD) system. Equations of motion for the combined building and the TLCD system are derived for multistorey building structures with rigid floors and plan and elevation irregularities. Major steps involved in optimal control of three‐dimensional irregular buildings equipped with a hybrid damper‐TLCD system are delineated. A wavelet‐based optimal control algorithm is applied to find the optimum control forces. Simulation results for control of two multistorey moment‐resisting space steel structures with vertical and plan irregularities show clearly that the hybrid damper‐TLCD control system significantly reduces responses of irregular buildings subjected to various earthquake ground motions as well as increases reliability and maximum operability during power failure. Copyright © 2005 John Wiley & Sons, Ltd.     

Nonlinear vibration control of a tall structure with tuned liquid column damper

The nonlinear vibration model of a structure with the tuned liquid column damper (TLCD) is established. TLCD is a successful structure control device. The damping of TLCD is amplitude-dependent and consequently nonlinear. Due to its complexity, the effective linear model is considered for investigating structure characteristics in almost all literatures. Moreover, the structure is usually modeled as a single degree of freedom model. However, the analytical solution for this nonlinear system is derived here. Further, it is found that the optimum design of TLCD for the suppression of vibration depends greatly on the structure parameters.     

Tuned liquid column damper for structural control

Summary. Tuned liquid column dampers (TLCDs) are energy dissipating substructures, which can be used to improve the dynamics of structures. The basic operating principle is an energy transfer from the vibrating host structure to the TLCD. A TLCD consists of a rigid piping system which is integrated in a structure and partially filled with liquid, preferably water. Its dynamics can be derived using the extended instationary Bernoullis equation for moving reference systems. Although both the construction and working principle of TLCDs differ from tuned mass dampers (TMDs), an analogy between the different types of absorber is given. Extending the passive TLCD by an actively controlled air-spring setup, and applying a suitable control strategy results in a novel hybrid active damper which combines both, the advantages of active control devices, and the salient features of TLCD, e.g., cheap and easy implementation into civil engineering structures, simple modification of the natural frequency and damping properties, little maintenance costs, a performance comparable to TMD as well as little additional weight if the TLCD is used as water reservoir for fire fighting. In numerical simulations of dynamically excited structures the proposed TLCD shows a considerable vibration reduction for wind and earthquake loading.     

自立式高耸结构风振控制方法研究

本文针对自立式高耸结构的风振控制装置及其设计方法开展研究。首先,根据自立式高耸结构的特点,设计了环形TMD、TLD和TLCD三种调频减振装置,并推导了其力学模型;随后,基于等效阻尼比的概念和我国规范的抗风设计方法,建立了自立式高耸结构风振控制的统一设计方法;最后,针对数值算例,进行了风振控制装置设计,并通过时程分析方法验证了该方法的有效性。研究结果表明,所设计的三种环形调频减振装置适用于自立式高耸结构的风振控制,建立的简化设计方法与时程分析的结果平均误差仅为5.37%,具有较高的精度,可用于自立式高耸结构的风振控制设计。     

汽车悬架磁流变减振器模型分析及半主动控制策略研究

用多项式模型作为磁流变减振器的力学模型,研究了传统"开-关"型半主动控制的阻尼力跳跃对汽车簧载质量振动加速度产生的不利影响,针对1/2汽车模型对具有磁流变减振器的汽车悬架简单模糊和自适应模糊神经半主动控制策略进行了数值仿真,基于数值仿真结果分析了各控制策略的效果.