磁流变阻尼器抗震应用的试验研究

将磁流变阻尼器安装在一 1∶ 6三层钢框架结构模型上 ,进行了模拟地震振动台试验 .试验采用不同的控制方法 ,了解了半主动变阻尼结构在地震波作用下的动力特性 ,同时对比研究了安装与未安装磁流变阻尼器时结构的动力反应试验结果 ,并对安装磁流变阻尼器结构的试验结果和弹塑性分析结果进行了分析 .     

不同控制策略下安装磁流变阻尼器的模型结构振动台试验与分析

本文对不同控制策略下安装有磁流变(MR)阻尼器的模型结构进行了振动台试验和分析。文中首先介绍了经典最优控制(COC)、瞬时最优控制(IOC)和线性二次高斯最优控制(LQG)等三种控制算法,然后对一首层安装有最近设计制造的MRF-04K型的MR阻尼器的、1/3比例的三层钢框架模型,进行了在两种被动控制和三种半主动控制等不同控制策略下的振动台试验,最后对模型结构地震反应的控制效果以及不同控制策略对控制效果的影响和控制稳定性进行了分析。研究表明,安装有MRF-04K阻尼器的结构控制系统具有良好的控制效果,无论是被动控制还是半主动控制,模型结构各层相对位移峰值均减小了45%左右,其均方根值均减小了70%左右,加速度反应峰值均减小了30%左右,其均方根值均减小了75%左右,从而验证了MRF-04K阻尼器是结构控制工程应用的一种理想的控制装置;研究还表明,在三种半主动控制策略中,基于LQG算法的半主动控制仅需模型结构的加速度反应的反馈信息,比基于IOC算法和COC算法的半主动控制     

基于磁流变阻尼器的压路机驾驶室悬置系统研究

鉴于冲击压路机的滚动冲击压实轮和路面冲击对牵引主机平顺性的影响,对驾驶室悬置系统进行研究.在原有的被动减振系统基础上进行改进,建立基于磁流变阻尼器的半主动悬置模型.将传统的驾驶室被动橡胶减振系统与基于磁流变阻尼器的半主动控制悬置系统进行仿真对比分析,结果表明对磁流变阻尼器进行合理的控制,半主动悬置下驾驶室加速度及俯仰加...     

磁流变阻尼器在建筑结构减振控制中的应用

建筑结构在外部激励下的振动控制一直以来是振动控制领域研究的热点。其中,半主动控制策略包含了被动控制和主动控制的优点,能更有效地提高建筑结构的抗震性能,减轻其在动力作用下的反应及损伤。基于磁流变阻尼器的半主动控制策略也有很大的发展,在实际工程中已有所应用。磁流变阻尼器的主要性能取决于磁流变液成分。综述国内外磁流变阻尼器的研究发展历程,及其在建筑结构减震控制中的应用,展望其在建筑结构减振控制应用中的发展趋势。     

变刚度半主动控制结构减振分析及安装位置探讨

分析了变刚度半主动控制结构的减振原理;基于单自由度结构和多自由度结构体系的仿真分析,对比分析了变刚度半主动控制结构的减振效果.通过MATLAB程序对结构动力方程的求解,基于程序可视化结果表明,变刚度半主动控制结构具有较好的减振特性,是结构振动控制一个很好的发展方向.在明确变刚度半主动控制结构减振效果的基础上,探讨了减振...     

建筑结构地震响应的MR阻尼器PID半主动控制

根据建筑结构的特点进行了结构上的简化计算,并采用了磁流变（MR）阻尼器的Bingham模型及PID半主动控制算法对建筑结构地震响应进行了半主动控制分析研究,并且与结构被动控制的效果进行了对比,数值结果表明：在EI-centro地震激励作用下,被动控制和半主动控制对结构地震响应的水平位移与速度取得了不同的控制效果;对结构的位移及速度的控制效果,MR半主动控制均明显的优于被动控制。     

磁流变阻尼器应用于压路机驾驶室悬置系统研究

鉴于冲击压路机作业条件恶劣及冲击轮和发动机的影响,牵引主机振动剧烈,严重影响驾乘人员舒适性.本文在原有的被动减振系统基础上进行改进,建立基于磁流变阻尼器的半主动悬置模型.以13t冲击压路机为研究对象,建立二自由度1/4车模型.将传统的驾驶室被动橡胶减振系统与基于磁流变阻尼器的半主动控制悬置系统进行仿真对比分析,结果表明...     

巨型框架多功能减振结构脉动风振反应的瞬时最优半主动控制

根据瞬时最优主动控制的原则,提出了同时控制位移、速度和加速度的最优主动控制策略,并利用磁流体阻尼器,对巨型框架多功能减振结构的脉动风振反应进行了半主动控制,表明磁流体阻尼器控制结构的半主动控制能显著减小主次框架的振动加速度,能有效地降低主框架的振动位移,其控制效果优于被动控制。     

车辆磁流变半主动悬架模糊滑模控制

为提高半主动悬架减振效果,将结合模糊控制理论的滑模控制算法应用于磁流变半主动悬架控制中,并通过Matlab/Simulink建立了磁流变阻尼器及悬架动力学模型,同时进行了仿真分析,结果表明,采用模糊滑模控制策略优于传统控制策略。     

MR阻尼器在空间网壳结构风振抑制中的控制策略影响规律研究

磁流变液(MR)阻尼器是一种新型智能材料抗风减振装置,它以适当方式和网壳结构结合,形成具有智能材料杆件的空间网壳结构,以达到抑制结构风振的目的。本文研究了控制策略对空间网壳结构的抗风减振效果的影响。研究表明,不同控制策略导致不同的减振效果。Passive-off控制策略的风振抑制效果较差,Passive-on控制策略对控制结构位移响应效果较好,但对控制速度和加速度效果不佳。半主动控制策略对控制结构的位移、速度和加速度响应均较理想。     

A modified friction damper for diagonal bracing of structures

In this paper, the dynamic behavior of a recently developed friction damper has been demonstrated. It is made from nine steel stripes and nine high strength steel bolts and is applied in the diagonal bracing of structures. This device has a square geometric shape and should be installed in the square spans. During this research work, a prototype of the modified friction damper was tested by a universal machine. Then the damper was installed inside a SDOF steel frame and tested by the shaking table under several earthquake excitations. For numerical assessment of the system, the model of SDOF frame was created in SAP2000 and analyzed under the same excitations which had been applied during the shaking table tests. By comparing the results obtained from SAP2000 to those of experimental tests, the validity of numerical modeling was proved. In order to assess the behavior of damper in multi-story buildings, the model of a four story frame, with and without the modified damper, was created in SAP2000 and analyzed under several seismic records. The results were indicating that the lateral displacements and the base shears of the multi-story building have been significantly reduced by the installation of this modified energy absorber and a considerable energy has been dissipated by the damping system.     

双态控制下磁流变阻尼结构的弹塑性地震反应分析

首先介绍了磁流变体的力学特性 ,以及由它制成的磁流变阻尼器的构造与性能。通过对磁流变阻尼器性能试验的数据进行分析研究 ,导出了其力学模型———Bingham模型的有关参数公式。然后 ,在此模型下利用半主动双态控制算法 ,对磁流变阻尼结构在地震作用下的弹塑性动力反应进行了分析。分析和研究结果表明 ,利用磁流变阻尼器对结构进行半主动控制能产生良好的减震效果。     

磁流变阻尼智能加固体系的试验研究

提出利用磁流变阻尼器(MRD)对有损伤结构进行智能加固。根据MRD的特点,结合我国抗震设计规范,给出MRD智能加固的三个等级性能目标,对其进行量化,并确定MRD智能加固的设计要点。利用MRD对一有损伤钢筋混凝土框-剪偏心结构进行抗震加固,并进行振动台试验。结果表明,采用MRD智能加固后的结构抗震性能大大提高,优于用被动控制方法加固的结构。     

A new control algorithm to protect nonlinear base‐isolated structures against earthquakes

Currently, nonlinear base isolation systems are widely used in the construction of earthquake resistant structures. However, they are found to be vulnerable in near‐fault regions as a result of long‐period pulses that may exist in near‐source ground motions. Various control strategies including passive, active and semi‐active control systems have been studied in order to handle this issue. In this study, a semi‐active control algorithm based on the different performance levels anticipated from an isolated building during different levels of ground shaking was developed. The proposed performance‐based algorithm is based on a modified version of the well‐known semi‐active skyhook control algorithm. A series of analyses were performed on the base‐isolated benchmark building, suggested by the American Society of Civil Engineers committee, subject to seven pairs of scaled ground‐motion records. The results proved that the new control algorithm is successful in improving structural and nonstructural performance of isolated buildings under near‐fault earthquakes. Copyright © 2012 John Wiley & Sons, Ltd.     

Energy‐based predictive algorithm for semi‐active tuned mass dampers

There are various control strategies proposed and implemented for the protection of structures against different types of dynamic excitations. Currently, semi‐active control devices are very popular due to their adaptability and low power requirement. In this paper, a novel energy‐based predictive (EBP) algorithm is proposed, and its effectiveness is studied when applied to semi‐active tuned mass damper (SATMD). The mechanical energy of the primary structure is taken as the key parameter to be used by the algorithm to predict a suitable value of the manipulated variable, the damping of the tuned mass damper (TMD). The choice of the damping is made such that the damping used at a time interval leads to the least possible mechanical energy of the primary structure. The efficacy of the proposed control algorithm is studied by employing the EBP algorithm on single‐story and multistory structures equipped with the SATMD. The performance of the proposed algorithm when applied to the SATMD is also compared with that with the passive TMD for similar parameters. The results of the study show that the implementation of the EBP algorithm leads to significantly reduced dynamic response as compared with the passive TMD. Furthermore, numerical studies are conducted to gain insight into the effect of various parameters such as the mass ratio, the TMD damping ratio, and the flexibility of the structure.     

磁流体阻尼器半主动控制结构的地震反应分析

对磁流变阻尼器的性能及恢复力模型进行了介绍,并对其参数进行了设计,提出了基于经典线性最优控制算法和瞬时最优控制算法的半主动控制律.通过对一装有七个MR阻尼器的七层框架结构的地震反应分析表明,基于这两种控制算法的半主动控制律是非常有效的,并且该半主动控制方法能够有效地减小结构的地震反应.     

Seismic performance evaluation of tall and nonseismic‐designed wall‐type structures by shaking table tests

Two 1/5‐scaled models of a nonseismic‐designed wall‐type structures were constructed and tested on a shaking table to evaluate their seismic performances. The prototype structure had shear walls only along the short side of the structure, which was a typical structural plan of apartment buildings constructed by tunnel forms before the seismic design code was enforced in Korea in 1989. Of the two models, one model was reinforced by steel angle sections placed on the walls and under the slabs for seismic retrofit. They were tested on a shaking table to investigate performance for earthquake ground excitations with various intensities. The experimental results showed that the nonseismic‐designed wall‐type structure without seismic retrofit failed to satisfy the life‐safety and collapse‐prevention performance objectives, whereas the retrofitted structure satisfied all the performance objectives. Copyright © 2009 John Wiley & Sons, Ltd.     

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。     

钢筋混凝土巨型框架结构及附单向TMD装置的减震结构振动台试验研究

为了研究钢筋混凝土巨型框架结构体系的抗震性能及其地震作用损伤机理,设计制作1/25的缩尺模型,并设计加工了一套调谐质量阻尼器（TMD）装置安装在模型结构顶部,进行振动台试验,得到结构的动力特性和位移响应,并对比分析了TMD的减震效果。结果表明：当在峰值加速度为0.140g的地震波作用后（相当于原型7度多遇地震）,模型结构处在弹性工作状态,在峰值加速度为0.400g的地震波作用后（相当于原型7度基本烈度）,模型结构出现轻微破坏,在峰值加速度为0.880g的地震波作用后（相当于原型7度罕遇地震）,模型结构出现中等破坏,该原型结构可以满足抗震设计的要求;TMD装置具有较好的减震效果。