高阶单步法控制MR智能隔震系统的试验研究

高阶单步法已成功地应用于结构非线性分析及考虑时滞的主动控制等，显示了它的稳定、精度高和计算迅速等特点。磁流变阻尼器是一种性能优良的智能阻尼器，它具有阻尼力可调范围宽、响应迅速且所需能量很少的特点。本文将磁流变（MR）阻尼器与普通橡胶隔震支座相结合，采用高阶单步算法和两种控制策略对结构进行振动控制。数值模拟分析与振动台试验结果表明：由MR阻尼器提供可调阻尼力的智能隔震控制系统能有效克服被动隔震最优控制频带窄的缺点，对较宽频域范围不同大小的地震激励均能提供最优控制。同时也表明该控制算法是一种能用于结构实际控制的变阻尼有效算法。     

基于瞬时最优算法的磁流变阻尼隔震结构半主动控制

采用瞬时最优控制算法，对附加了磁流变阻尼器的多自由度隔震结构进行了半主动控制的数值模拟。首先，将被动隔震装置——叠层钢板橡胶垫与磁流变阻尼器相结合，形成磁流变智能隔震系统。其次，根据瞬时最优控制算法的基本原理，针对磁流变阻尼器的特点，建立与之相适应的半主动控制算法。最后，以六层隔震结构为例，进行数值分析。比较了被动与半主动控制的结构反应，并得到较好的控制效果。     

多层建筑结构水平剪扭-竖向地震反应的智能复合隔震控制

本文在提出了“碟形弹簧-橡胶隔震垫”和MR阻尼器组合而成的智能复合隔震系统的基础上，建立了智能复合隔震系统对多层建筑结构“水平剪扭-竖向”地震反应控制的设计计算方法。提出了智能复合隔震系统对建筑结构水平地震反应的模糊半主动控制策略和对建筑结构竖向地震反应的被动控制方法。以一个五层框架结构为例进行了仿真分析。分析结果表明，本文提出的智能复合隔震系统是一种十分简单和有效的隔震系统。它可克服建筑结构常规隔震系统的两个主要缺点，有效地抑制多层建筑结构的多维地震反应。     

基于自供电磁流变阻尼器的隔震高架桥半主动控制

为解决结构振动控制的能量源问题,提出了一种新型自供电MR阻尼器智能减振系统。该系统由电磁调节式MR阻尼器、齿条齿轮加速器、永磁电机与控制器组成。基于广泛采用的隔震高架桥两自由度线性模型,定义了位移控制性能评价指标,引入了在汽车悬架系统设计中常用的Sky-hook控制策略,对隔震高架桥的减震性能进行了仿真分析。结果表明:通过优化设计的参数,自供电MR阻尼器的LQR-Clipped半主动控制与Skyhook控制都可以完全达到其相应的采用外部供电的MR阻尼器的控制效果,且接近理想的主动控制结果。     

巨-子结构智能隔震体系抗震性能研究

针对巨-子结构隔震体系,在隔震层处或子结构顶部与主结构连接处,施加SMA-压电智能复合阻尼器,从而形成巨-子结构智能隔震体系。本文通过限界Hrovat最优控制算法设计了巨-子结构智能隔震体系的半主动控制器,在此基础上,对巨-子结构智能隔震体系进行了Simulink控制效果仿真分析,同时比较了控制装置安装位置的不同对结构控制效果的影响,并与普通隔震结构的减震效果进行了对比。研究结果表明,智能隔震控制1（隔震层加控制装置）和智能隔震控制2（子结构顶部加控制装置）2种控制方案在控制结构的位移方面效果相差不大。总体而言,智能隔震控制2对于控制子结构单元顶部的绝对加速度效果更为显著,但是相对于普通隔震而言,特别是在控制隔震层位移方面2种方案都具有较好的控制效果。实施智能控制可以有效改善巨-子结构被动控制体系的抗震性能,并能降低隔震结构在遭受强震时由于隔震层出现过大位移导致结构倾覆的危险。     

带智能磁流变阻尼器的层间隔震混合控制研究

为了进一步提高层间隔震体系的整体抗震性能,提出在层间隔震体系中附设MR智能磁流变阻尼器控制装置,构成新型的混合层间隔震控制体系。通过对某实际工程算例的非线性仿真分析,系统地研究了这种新型混合智能层间隔震控制体系的有效性,并与传统被动层间隔震减震效果进行了对比。     

磁流变智能隔震系统研究与应用现状

磁流变智能隔震系统作为一种新型隔震减震系统,克服了传统被动隔震结构的隔震层一经确定其性能参数将无法改变的缺点,可以同时对上部结构加速度和隔震层位移反应进行有效控制,因而适用于城市中大量重要建筑的地震反应控制.文中对其进行了研究与应用现状的介绍,具体包括磁流变阻尼器的研制、智能控制算法的编制和振动台试验研究等几部分,其中包括国内外取得的一些最新研究成果,还对该技术在工程中的应用情况进行了介绍.     

安装复合MR阻尼器的结构振动台试验研究

对不同控制策略下安装有复合MR(磁流变)阻尼器的模型结构进行了振动台试验研究.在El Centro地震动激励下,基于线性二次高斯(LQG)和广义预测(GP)两种控制算法,针对半主动控制系统、MR阻尼器以恒定电流(-0.5A(Passive-on 1)、0A(Passive-off)、2A(Passive-on 2)的控制系统,以及由半主动控制方式和基础隔震组合而成的混合控制系统,在WINCON/SIMULINK实时控制软件平台下对一个1:4的三层钢框架模型进行了地震模拟振动台试验.试验结果表明:基于复合MR阻尼器的控制系统是有效的,无论是被动控制、半主动控制还是混合控制,都显著降低了模型结构各层的加速度、位移响应;复合MR阻尼器在不通入电流时具有一定的被动控制效果;采用考虑时滞自补偿的广义预测控制效果要好于LQG控制,并且这两种控制策略的都能以较被动控制小的控制力达到较好的控制效果.     

带裙房高层建筑地震反应控制振动台试验研究

2002年9月在香港理工大学成功地进行了带裙房高层建筑地震反应控制试验研究。设计和制作的结构模型是带3层裙房的12层高楼剪切模型,在裙房顶层与主楼之间安装单MR阻尼器形成MR阻尼器耦联结构模型。MR阻尼器采用美国LORD公司摩擦型MR阻尼器,并且选用其配套产品计算机电流控制器对其进行控制,控制系统采用德国dSPACE公司实时控制系统。对独立主楼、独立裙房和原结构模型的动力特性进行了辨识;对结构模型进行了El Centro地震动作用下的地震反应振动台试验;以作者提出的MR阻尼器半主动逻辑控制算法,对MR阻尼器耦联的结构模型进行了地震反应振动台试验。试验结果表明：用MR阻尼器耦联主楼与裙房,采用半主动逻辑控制方法进行控制,能有效抑制主楼的鞭梢效应并使主楼和裙房的地震反应减小。     

屋盖MR智能隔震系统对升船结构顶部厂房地震鞭梢效应的模糊控制

基于抑制升船结构顶部厂房地震鞭梢效应的目的，本文提出了升船结构顶部厂房屋盖MR智能隔震模糊控制的思想。文中，在建立屋盖智能隔震升船结构计算力学模型的基础上，建立了屋盖MR智能隔震系统对升船结构顶部厂房地震反应模糊控制的设计计算方法。文中并以中国某大坝巨型升船结构为背景，设计了屋盖MR智能隔震系统对升船结构顶部厂房地震反应模糊控制的控制系统。仿真分析和对MR阻尼器的参数研究表明，安装合适的屋盖MR智能隔震系统并采用模糊控制策略能有效地抑制具有不确定参数升船结构顶部厂房地震反应的鞭梢效应，且模糊控制器能保持较好的稳定性能。     

Semi‐active control of sliding isolated bridges using MR dampers: an experimental and numerical study

Sliding base‐isolation systems used in bridges reduce pier drifts, but at the expense of increased bearing displacements under near‐source pulse‐type earthquakes. It is common practice to incorporate supplemental passive non‐linear dampers into the isolation system to counter increased bearing displacements. Non‐linear passive dampers can certainly reduce bearing displacements, but only with increased isolation level forces and pier drifts. The semi‐active controllable non‐linear dampers, which can vary damping in real time, can reduce bearing displacements without further increase in forces and pier drifts; and hence deserve investigation. In this study performance of such a ‘smart’ sliding isolation system, used in a 1:20 scaled bridge model, employing semi‐active controllable magneto‐rheological (MR) dampers is investigated, analytically and experimentally, under several near‐fault earthquakes. A non‐linear analytical model, which incorporates the non‐linearities of sliding bearings and the MR damper, is developed. A Lyapunov control algorithm for control of the MR damper is developed and implemented in shake table tests. Analytical and shake table test results are compared. It is shown that the smart MR damper reduces bearing displacements further than the passive low‐ and high‐damping cases, while maintaining isolation level forces less than the passive high‐damping case. Copyright © 2005 John Wiley & Sons, Ltd.     

Semi‐active neuro‐control for base‐isolation system using magnetorheological (MR) dampers

Vibration mitigation using smart, reliable and cost‐effective mechanisms that requires small activation power is the primary objective of this paper. A semi‐active controller‐based neural network for base‐isolation structure equipped with a magnetorheological (MR) damper is presented and evaluated. An inverse neural network model (INV‐MR) is constructed to replicate the inverse dynamics of the MR damper. Next, linear quadratic Gaussian (LQG) controller is designed to produce the optimal control force. Thereafter, the LQG controller and the INV‐MR models are linked to control the structure. The coupled LQG and INV‐MR system was used to train a semi‐active neuro‐controller, designated as SA‐NC, which produces the necessary control voltage that actuates the MR damper. To evaluate the proposed method, the SA‐NC is compared to passive lead–rubber bearing isolation systems (LRBs). Results revealed that the SA‐NC was quite effective in seismic response reduction for wide range of motions from moderate to severe seismic events compared to the passive systems. In addition, the semi‐active MR damper enjoys many desirable features, such as its inherent stability, practicality and small power requirements. The effectiveness of the SA‐NC is illustrated and verified using simulated response of a six‐degree‐of‐freedom model of a base‐isolated building excited by several historical earthquake records. Copyright © 2006 John Wiley & Sons, Ltd.     

Seismic response control of frame structures using magnetorheological/electrorheological dampers

Semi‐active control of buildings and structures for earthquake hazard mitigation represents a relatively new research area. Two optimal displacement control strategies for semi‐active control of seismic response of frame structures using magnetorheological (MR) dampers or electrorheological (ER) dampers are proposed in this study. The efficacy of these displacement control strategies is compared with the optimal force control strategy. The stiffness of brace system supporting the smart damper is also taken into consideration. An extensive parameter study is carried out to find the optimal parameters of MR or ER fluids, by which the maximum reduction of seismic response may be achieved, and to assess the effects of earthquake intensity and brace stiffness on damper performance. The work on example buildings showed that the installation of the smart dampers with proper parameters and proper control strategy could significantly reduce seismic responses of structures, and the performance of the smart damper is better than that of the common brace or the passive devices. The optimal parameters of the damper and the proper control strategy could be identified through a parameter study. Copyright © 2000 John Wiley & Sons, Ltd.     

Real‐time hybrid testing of a smart base isolation system

Real‐time hybrid testing is a very effective technique for evaluating the dynamic responses of rate‐dependent structural systems subjected to earthquake excitation. A smart base isolation system has been proposed by others using conventional low‐damping isolators and controllable damping devices such as magnetorheological (MR) dampers to achieve specified control target performance. In this paper, real‐time hybrid tests of a smart base isolation system are conducted. The simulation is for a base‐isolated two‐degrees‐of‐freedom building model where the superstructure and the low‐damping base isolator are numerically simulated, and the MR damper is physically tested. The target displacement obtained from the step‐by‐step integration of the numerical substructure is imposed on the MR damper, which is driven by three different control algorithms in real‐time. To compensate the actuator delay and improve the accuracy of the test, an adaptive phase‐lead compensator is implemented. The accuracy of each test is investigated by using the root mean square error and the tracking indicator. Experimental results demonstrate that the hybrid testing procedure using the proposed actuator compensation techniques is effective for investigating the control performance of the MR damper in a smart base isolation system. Copyright © 2013 John Wiley & Sons, Ltd.     

可调滞回模型的磁流变阻尼器及其试验

本文在现在磁流变阴尼器性能研究的基础上，提出了可调滞回模型的磁流变阻尼器及其试验方法，并进行理论、试验及算例分析。首先，根据恒定电流下磁流变阻尼器的阻尼力滞力特性，利用磁流变材料特性的电流（即磁场）可控特点，建立了变电流下的阻尼力滞回模型；其次，在中通过电路板控制外加电流与装置变形间的函数关系，实现了变电流调节的阻尼力滞回模型；最后，将磁流变阻尼器与橡胶隔震装置结合，形成智能磁流变隔夺装置，并对一个单自由度隔震结构进行了数值仿真分析。     

Experimental performance evaluation of an equipment isolation using MR dampers

Critical non‐structural equipments, including life‐saving equipment in hospitals, circuit breakers, computers, high technology instrumentations, etc., are vulnerable to strong earthquakes, and the failure of these equipments may result in a heavy economic loss. In this connection, innovative control systems and strategies are needed for their seismic protections. This paper presents the performance evaluation of passive and semi‐active control in the equipment isolation system for earthquake protection. Through shaking table tests of a 3‐story steel frame with equipment on the first floor, a magnetorheological (MR)‐damper together with a sliding friction pendulum isolation system is placed between the equipment and floor to reduce the vibration of the equipment. Various control algorithms are used for this semi‐active control studies, including the decentralized sliding mode control (DSMC) and LQR control. The passive‐on and passive‐off control of MR damper is used as a reference for the discussion on the control effectiveness. Copyright © 2008 John Wiley & Sons, Ltd.     

基于半主动控制的MR阻尼器控制力优化

本文研究半主动控制系统中磁流变(MR)阻尼器的控制力优化问题,从而提高MR阻尼器的半主动控制效果。文中首先建立了多自由度结构MR阻尼器控制系统的运动方程;然后根据MR阻尼器的出力特性提出了结构控制的半主动控制律,并对控制率中MR阻尼器的最大控制力设计值提出了不同的优化取值方法;最后仿真分析了MR阻尼器的不同最大控制力设计值对不同自由度结构的控制效果。研究表明,当设计值取最优控制力的平均绝对值或均方根值时,MR阻尼器的最大控制力比最优控制力的最大值降低了85%,而控制效果降低不多,可以满足对结构的控制要求;降低最大控制力设计值后,不但可以充分发挥MR阻尼器的出力性能,而且可以缩小MR阻尼器的设计尺寸,便于工程应用。     

Smart Semi-active PID-ACO control strategy for tower vibration reduction in Wind Turbines with MR damper

Wind turbine technology is well known around the globe as an eco-friendly and effective renewable power source. However, this technology often faces reliability problems due to structural vibration. This study proposes a smart semi-active vibration control system using Magnetorheological (MR) dampers where feedback controllers are optimized with nature-inspired algorithms. Proportional integral derivative (PID) and Proportional integral (PI) controllers are designed to achieve the optimal desired force and current input for MR the damper. PID control parameters are optimized using an Ant colony optimization (ACO) algorithm. The effectiveness of the ACO algorithm is validated by comparing its performance with Ziegler-Nichols (Z-N) and particle swarm optimization (PSO). The placement of the MR damper on the tower is also investigated to ensure structural balance and optimal desired force from the MR damper. The simulation results show that the proposed semi-active PID-ACO control strategy can significantly reduce vibration on the wind turbine tower under different frequencies (i.e., 67%, 73%, 79% and 34.4% at 2 Hz, 3 Hz, 4.6 Hz and 6 Hz, respectively) and amplitudes (i.e. 50%, 58% and 67% for 50 N, 80 N, and 100 N, respectively). In this study, the simulation model is validated with an experimental study in terms of natural frequency, mode shape and uncontrolled response at the 1st mode. The proposed PID-ACO control strategy and optimal MR damper position is also implemented on a lab-scaled wind turbine tower model. The results show that the vibration reduction rate is 66% and 73% in the experimental and simulation study, respectively, at the 1st mode.