磁流变阻尼器智能隔震振动台试验研究

采用MR阻尼器和改进的实时控制程序进行了振动台半主动控制试验。通过与基础固定、基础隔震结构进行对比,验证了该MR阻尼器在瞬时最优、模糊逻辑控制、位移限值控制算法以及零场控制和满场控制的效果,显示了相对于一般基础隔震的优越性。试验结果表明:智能隔震系统不仅能够大幅度减小隔震层的水平位移,有效地保护隔震层和隔震支座,上部结构层间位移反应和加速度反应也得到了有效的控制。采用MR阻尼器的智能隔震系统能够有效地改善隔震结构的性能,大大提高隔震建筑的安全可靠性。     

磁流变阻尼器在基础智能隔震建筑中的研究

针对橡胶隔震垫作为一种被动控制装置,存在最优控制范围窄的局限性。将磁流变阻尼器与橡胶隔震垫相结合,组成智能基础隔震系统应用于结构振动控制中,数值模拟分析了在地震力作用下原结构,普通隔震结构,隔震层附加MR阻尼器在Passive—off状态,Passive—on状态和磁流变阻尼器半主动智能状态下结构的反应。试验结果表明,结构在磁流变阻尼器半主动智能状态下控制效果最优,能有效克服被动隔震最优控制频带窄的缺点,其相对一般被动隔震装置,能同时减小隔震层位移,上部结构层间位移和各层最大加速度。     

MR智能基础隔震结构抗震性能分析

研究MR智能基础隔震结构的抗震性能。首先,建立该混合控制结构的数学模型,其中应用双线型恢复模型描述橡胶垫隔震层的弹塑性特性,运用自适应神经网络模糊系统(ANFS)计算MR阻尼器的控制力。在SIMULINK环境下对控制结构进行仿真动力分析。并对具体结构进行地震作用下的时程反应分析,仿真分析表明:自适应神经网络模糊系统可以有效地应用到结构控制中,并证实了MR基础隔震结构是一种性能优异的智能控制系统。     

屋盖MR智能隔震系统对升船机地震反应的智能控制

升船结构很难采用常规的结构振动控制方法来抑制其顶部的地震反应,故提出利用MR智能阻尼器的屋盖MR智能隔震系统来减小升船结构顶部厂房的地震侧移反应和柱底的地震反应。MR智能阻尼器是利用磁流变液产生阻尼力的半主动控制装置,该装置具有机械构造简单,动力范围宽广,只需要较小的能量输入就能产生大的输出力,因此被证明能有效运用于土木工程结构来抵抗强烈地震和强风。本文阐述了MR阻尼器的力学性能,建立了屋盖MR智能隔震升船结构的控制方程,在此基础上实现MR模糊半主动控制。应用本文提出的方法对升船结构屋盖MR智能隔震系统进行仿真计算结果表明:模糊半主动控制使升船结构顶部层间位移和柱底弯矩均有明显的减小,能有效抑制升船结构顶部厂房的地震鞭梢效应。     

大坝升船机地震鞭梢效应智能控制的振动台试验

大坝升船机顶部厂房与底部塔柱结构之间的侧移刚度突变造成了顶部厂房强烈的地震鞭梢效应。针对此问题,本文进行了屋盖MR智能隔震系统对大坝升船机地震鞭梢效应智能控制的振动台试验研究。屋盖MR智能隔震系统由隔震垫、磁流变(MR)阻尼器及控制系统组成,安装在厂房的柱子顶部。首先采用修正的Bingham模型得到数据来训练神经网络以反映MR阻尼器的逆向动力特性,然后与模糊算法结合通过dSPACE实时控制系统得到阻尼器的最优控制信号。试验结果表明:模糊-神经控制方法能有效控制屋盖MR智能隔震系统,使得大坝升船机顶部厂房的鞭梢效应明显减小,排架柱顶位移减小了50%,隔震层相对位移减小了57%。     

大平台多塔楼新型隔震体系的智能磁流变控制

本文将隔震技术应用到大平台多塔楼结构中,研究了这种新型隔震体系的抗震性能,并将磁流变(MR)阻尼器设置于隔震层,探讨了这种新型隔震体系智能磁流变控制的减震效果.文中以北京通惠家园某典型小区为研究对象,建立了大平台多塔楼新型隔震减震体系的运动方程,考虑了隔震支座的非线性.本研究中MR阻尼器的半主动控制算法选用限幅最优控制算法,其主控制器采用H2/LQG方法来设计.仿真分析结果表明,这种新型隔震体系可以有效地减小上部住宅结构与下部平台的地震反应,为提高大平台多塔楼结构的抗震安全性提供了一条崭新的途径.采用MR阻尼器与这种新型隔震体系相结合可以进一步减小隔震结构下部平台的地震反应与隔震层的非线性反应,提高这种新型隔震体系的抗震安全性.     

滑动摩擦基础隔震房屋实用设计方法

一、总则 1.适用性和设防目标 滑动摩擦和弹塑性阻尼器相结合的基础隔震体系,是以房屋基底设置的水平滑动摩擦层隔离地震波向上部传播、并以弹塑性阻尼器控制基底滑移的一种隔震、减震体系,     

基于短时傅里叶变换的可变摩擦基础隔震系统

近断层地震作用可能使被动控制的基础隔震系统产生过大的加速度反应。为克服被动控制隔震系统这一局限性,针对含有可变摩擦阻尼器的基础隔震系统,提出了一种基于对场地加速度信号短时傅里叶变换的控制算法,预估隔震的失效,即时改变隔震层的摩擦阻尼。在三种不同类型的地震波作用下,对一个含有叠层橡胶支座和可变摩擦阻尼器的多自由度层模型使用Simulink进行时程分析。分析表明,该算法控制下的半主动隔震系统能够有效改变被动控制隔震系统对近断层地震的放大效应,限制隔震层的位移。     

基础隔震高层建筑影响因素的理论分析

对采用基础隔震的高层建筑进行了三维有限元分析计算,研究了不同结构体系、双向地震作用、P-△效应以及加速度反应等对基础隔震高层建筑的影响.通过以上的研究,得出了结论:同一结构体系在相同地震波作用下,隔震结构的层间剪力比非隔震结构的层间剪力减小一个数量等级;不同结构体系在相同地震波作用下,隔震结构的位移随层数的变化趋势不一致;同一结构在不同地震波作用下,建筑物的地震反应相差较大;在建筑物中某些构件需要考虑双向地震波作用效应;隔震建筑物可以不考虑P-△效应;高层隔震建筑物的加速度反应不同于非隔震建筑物的加速度反应.结果表明,基础隔震技术可以应用于高层建筑.     

智能隔震结构能量响应初步分析及控制效率评判

本文采用能量响应的观点揭示被动和智能隔震体系的减震机理,评判采用三种不同控制算法时智能隔震结构的控制效果。采用解析手段,导出了被动和智能隔震体系的累积能量平衡方程和结构瞬时能量传递的定性关系,揭示智能隔震在抑制结构能量响应方面的优势。在对能量传递取得定性认识的基础上,选用几个主要的能量响应指标,对被动隔震与智能隔震的能量响应进行分析,并对比采用三种不同控制算法的智能隔震结构能量响应规律。文末选用本文作者承担设计过的一个实际隔震工程作为算例,分别比较了输入两种不同地震波和两种不同地震强度水准时各种算法的控制效果。结果表明,本文作者建立的序列最优控制算法能更有效地抑制能量响应,再次显示了该算法综合性能优于现有两种结构最优控制算法。     

Smart platform for microvibration control of high-tech industry facilities

Recently, the microvibrations of high technology facilities resulting from nearby traffic loads have attracted significant attention. Considerable research aimed at protecting high-tech equipment due to nearby road and rail traffic has focused on vibration isolation systems. These isolation systems include passive-base isolation systems, smart base isolation systems, passive mounts, and active tables that are used mainly to isolate a small quantity of high-tech equipment. In this study, a smart platform was developed to control the microvibrations of high-technology facilities. Train-induced ground acceleration was generated as a nearby traffic load and a magnetorheological damper was used to compose a smart isolation platform. A fuzzy logic controller was used as a control algorithm that was optimized using a multi-objective genetic algorithm. The microvibration control performance of a smart isolation platform was compared with that of a conventional passive isolation platform. A series of parametric studies were performed to optimize the design of a passive isolation platform. Numerical analysis showed that a smart isolation platform can effectively control the microvibrations of a high-technology facility subject to train-induced excitation.     

拟负刚度磁流变智能隔震系统振动台试验研究

为研究拟负刚度控制算法及磁流变智能隔震系统的有效性和适应性,将自主研发的最大出力为10kN的磁流变液阻尼器(MRFD)安装在隔震层中心,并选取4条有代表性的远近场地震波,峰值加速度由0.1g~0.9g逐步增大,分别对普通隔震结构、输入电流为0A和1A的被动控制结构以及采用基于位移的拟负刚度(DPNS)控制算法的智能控制结构进行振动台试验。通过对结构响应和阻尼器响应的对比分析,研究拟负刚度控制算法的减震效果和磁流变智能控制系统的耗能特性。结果表明：恒定电流为0A的被动控制可同时降低上部结构反应和隔震层位移,但是减震效果有限;恒定电流为1A的被动控制对隔震层位移降低效果明显,但是在多遇地震及远场地震作用下放大了上部结构反应;DPNS控制可同时降低隔震层位移和多遇、设防地震甚至罕遇地震作用下上部结构的反应,且适应于不同的地震动特性;试验中控制系统存在的时滞效应使得DPNS控制力在多遇、设防地震作用下具有较小值,同时罕遇地震作用下具有较强的耗能能力。     

Analytical and Numerical Study of a Smart Sliding Base Isolation System for Seismic Protection of Buildings

The seismic response of a single–story steel building frame with a smart base isolation system is evaluated. The isolation system consists of sliding bearings combined with an adaptive fluid damper. The damping capacity of the fluid damper can be modulated in real time based on feedback from the earthquake ground motion and superstructure response. The adaptive capabilities of the fluid damper enable the isolation system displacement to be controlled while simultaneously limiting the interstory drift response of the superstructure. This paper concentrates on the development of analytical models of the smart isolation system and control algorithms for operation of the system. In general, the results from numerical simulations demonstrate that, for disparate earthquake ground motions, the smart isolation system is capable of simultaneously limiting both the response of the isolation system and the superstructure.     

Fuzzy Control of Base-Isolation System Using Multi-Objective Genetic Algorithm

Abstract:   In this study, a friction pendulum system (FPS) and a magnetorheological (MR) damper are employed as the isolator and supplemental damping device, respectively, of a smart base-isolation system. Neuro-fuzzy models are used to represent dynamic behavior of the MR damper and FPS. A fuzzy logic controller (FLC) is used to modulate the MR damper so as to minimize structural acceleration while maintaining acceptable base displacement levels. To this end, a multi-objective optimization scheme that uses a nondominated multi-objective genetic algorithm (NSGA-II) is used to optimize parameters of membership functions and find appropriate fuzzy rules. To demonstrate the effectiveness of the proposed multi-objective genetic algorithm for FLC, a numerical study of a smart base-isolation system is conducted using several historical earthquakes. It is shown that the proposed method can find optimal fuzzy rules and that the NSGA-II-optimized FLC outperforms not only a passive control strategy but also a human-designed FLC and a conventional semiactive control algorithm.     

Smart outrigger damper system for response reduction of tall buildings subjected to wind and seismic excitations

The outrigger damper system has recently been proposed to reduce the dynamic response of tall buildings subjected to lateral loads. Previous studies have shown that the outrigger damper system could effectively increase the response reduction capacity of tall buildings. The outrigger damper system was used not only for a response reduction of tall buildings, but also for adjusting the differential column shortening. When an outrigger damper system is designed optimally for wind or earthquake loads, it shows good control performance against each target excitation. On the other hand, the outrigger damper system designed for the wind load cannot effectively control the seismic responses and vice versa. This study examined the control performance of a smart outrigger damper system for reducing both the wind and seismic responses. The smart outrigger damper system was comprised of magnetorheological dampers. A fuzzy logic control algorithm, which was optimized by a multi-objective genetic algorithm, was used to control the smart outrigger damper system. Numerical analysis showed that the smart outrigger damper system could provide superior control performance for the reduction of both wind and earthquake responses compared to the general outrigger system and passive outrigger damper system.     

Theoretical and experimental study on seismic response control on top of Three-Gorges ship lift towers using magnetorheological intelligent isolation system and its key technique

A vertical ship lift under earthquake excitation may suffer from a whipping effect due to the sudden change of building lateral stiffness at the top of the ship lift towers. This paper proposes a roof magnetorheological (MR) intelligent isolation system to prevent the seismic whipping effect on machinery structures. Theoretically, the dynamic models of MR damper and the mechanical model of ship lift was established, the inverse neural network controlling algorithm was proposed and the fundamental semi-active control equation for the Three-Gorges ship lift where the MR intelligent isolation system was installed was deduced. Experimentally, the experimental model of the ship lift was given, the vibrating table experiment of the MR intelligent isolation system controlling the whipping effect was carried out and the results of the inverse neural network control strategy and passive isolation strategy were compared. In practical aspect, the large-scale MR damper (500 kN) and a sliding support with limited stiffness were designed and fabricated. It was proven that the MR intelligent isolation system with proper control strategy can greatly reduce the seismic whipping effect on the top workshop of the ship lift and be simple and effective enough to be applied to real engineering structures.     

磁流变弹性体及其隔震(振)应用研究进展

为促进磁流变弹性体及其隔震(振)技术的发展,系统总结了磁流变弹性体在土木工程领域的研究、应用现状和存在的问题.综述了磁流变弹性体的材料组成、制备方法、本构模型,对比了材料、制备方法对磁流变弹性体磁致力学性能的影响;总结了磁流变弹性体隔震(振)支座研究开发方面的最新成果,比较了几类磁流变弹性体智能隔震(振)支座和不同控制...     

工程结构的基础隔震与隔震系统

本文阐述了工程结构的基础隔震概念和隔震系统的组成、作用以及多种适用的隔震器、阻尼器、地基微震动与风反应的控制装置。     

MOGA-Based Structural Design Method for Diagrid Structural Control System Subjected to Wind and Earthquake Loads

An integrated optimal structural design method for a diagrid structure and control device was developed. A multi-objective genetic algorithm was used and a 60-story diagrid building structure was developed as an example structure. Artificial wind and earthquake loads were generated to assess the wind-induced and seismic responses. A smart tuned mass damper (TMD) was used as a structural control system and an MR (magnetorheological) damper was employed to develop a smart TMD (STMD). The multi-objective genetic algorithm used five objectives including a reduction of the dynamic responses, additional stiffness and damping, mass of STMD, capacity of the MR damper for the integrated optimization of a diagrid structure and a STMD. From the proposed method, integrated optimal designs for the diagrid structure and STMD were obtained. The numerical simulation also showed that the STMD provided good control performance for reducing the wind-induced and seismic responses of a tall diagrid building structure.