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1.
摩擦阻尼器是一种构造简单的耗能减振装置,已应用于国内外多座新建建筑的抗震设计和已建建筑的抗震加固.半主动磨擦阻尼器则通过调整阻尼器的起滑力来改善被动摩擦阻尼器的耗能减振性能。本文研究了被动及半主动摩擦阻尼器对于高耸塔架结构地震反应的减振效果。为满足摩擦阻尼器对高耸塔架结构风振控制的特殊需要,本文建立了合肥电视塔的空间桁架有限元模型和串联多自由度体系模型,并在形成控制力变换矩阵和计算摩擦阻尼器两端的相对位移的过程中综合地运用了这两种力学模型。在半主动摩擦阻尼器的控制策略方面,本文提出了一种基于次优控制理论的半主动控制策略.本文研究表明,摩擦阻尼器可以抑制高耸塔架结构的地震反应.而半主动摩擦阻尼辞的耗能减振效果明显优于被动摩擦阻尼器.  相似文献   

2.
Vibration control systems are being used increasingly worldwide to provide enhanced seismic protection for new and retrofitted buildings. This paper presents a new vibration control system on the basis of a seesaw mechanism with viscoelastic dampers. The proposed vibration control system comprises three parts: brace, seesaw member, and viscoelastic dampers. In this system, only tensile force appears in bracing members. Consequently, the brace buckling problem is negligible, which enables the use of steel rods for bracing members. By introducing pre‐tension in rods, long steel rods are applicable as bracing between the seesaw members and the moment frame connections over some stories. Seesaw mechanisms can magnify the damper deformation according to the damper system configuration. In this paper, first, the magnification factor, that is, the ratio of the damper deformation to the story drift, is delivered, which includes the rod deformation. Results of a case study demonstrate that the magnification factor of the proposed system is greater than unity for some cases. Seismic response analysis is conducted for steel moment frames with the proposed vibration control system. Energy dissipation characteristics are examined using the time‐history response results of energy. The maximum story drift angle distributions and time‐history response results of displacement show that the proposed system can reduce the seismic response of the frames effectively. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

3.
压电材料是一种新型智能材料。本文将压电材料和被动摩擦阻尼器相结合设计出一种新型智能摩擦阻尼器,并采用基于经典最优控制理论的半主动控制策略对高耸钢塔结构风振反应的控制进行了研究,对国内即将兴建的第一高钢电视塔──合肥翡翠电视塔进行了算例分析。为满足摩擦阻尼器对高耸钢塔结构风振控制的特殊需要、文中还建立了房耸钢塔结构的空间桁架有限元模型和串联多自由度体系模型,并在形成广义控制力作用位置矩阵和计算摩擦阻尼器两端的相对位移的过程中综合地运用了这两种力学模型。本文研究表明,压电材料智能摩擦阻尼器可以有效地抑制高耸钢塔结构的风振反应。  相似文献   

4.
半主动磁流变阻尼控制结构的地震反应分析   总被引:35,自引:6,他引:29  
本文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,提出了基于现代最优控制理论的半主动控制方法.计算实例分析结果表明,采用磁流变阻尼器对结构进行半主动控制能够有效地减小结构的地震反应.  相似文献   

5.
基于AFSMC算法的结构非线性振动MR控制与仿真分析   总被引:2,自引:0,他引:2  
作为最近发展起来的高性能半主动控制装置,磁流变阻尼器通过改变磁场强度来调节控制力,可靠度高,体积小,出力大,并且具有Fail-Safe的特点,是一种具有广泛应用前景的新型结构控制装置。本文主要研究结构非线性振动的磁流变阻尼半主动控制。首先采用我们提出的自适应模糊滑模控制(AFSMC)算法得到了结构非线性振动的主动控制力,然后参照主动控制力,提出和仿真实现了结构非线性振动的磁流变阻尼半主动控制。最后,针对3层和20层benchm ark非线性模型,每层均设置一个磁流变阻尼器,对在给定的地震动下的结构响应进行了计算,分析了半主动控制跟踪主动控制的效果,并且对于半主动控制下的结构位移响应、加速度响应等各项指标也进行了对比分析。仿真结果表明,由于自适应模糊滑模控制算法与半主动控制算法相结合可以很好地实现结构非线性振动的半主动控制,所以能够得到令人满意的控制结果。  相似文献   

6.
相邻结构地震反应MR阻尼器控制的仿真分析   总被引:2,自引:0,他引:2  
本文仿真分析了应用磁流变(MR)阻尼器对相邻结构地震反应的控制效果,为进一步开展模型试验研究奠定了基础。建立了地震激励下相邻结构MR阻尼器控制系统的运动方程,提出了描述MR阻尼器阻尼力滞回特性的改进S igmoid模型,分别对应用开关控制、半主动控制以及最小或最大电流被动控制的四种控制方法的相邻结构地震反应的控制效果进行了仿真分析。结果表明,在相邻结构间连接安装MR阻尼器可以有效地控制相邻结构的地震反应,且开关控制方法和半主动控制方法的控制效果均好于两种被动控制方法,体现了MR阻尼器阻尼力可调的优点;在四种控制方法中,半主动控制方法的控制效果最好,体现了MR阻尼器阻尼力具有连续调节能力的优点;若能解决MR阻尼器的剩磁问题,半主动控制方法的控制效果会得到进一步的提高。  相似文献   

7.
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。  相似文献   

8.
Adaptive base-isolation of civil structures using variable amplification   总被引:1,自引:0,他引:1  
Semi-active dampers are used in base-isolation to reduce the seismic response of civil engineering structures. In the present study, a new semi-active damping system using variable amplification will be investigated for adaptive baseisolation. It uses a novel variable amplification device (VAD) connected in series with a passive damper. The VAD is capable of producing multiple amplification factors, each corresponding to a different amplification state. Forces from the damper are amplified to the structure according to the current amplification state, which is selected via a semi-active control algorithm specifically tailored to the system's tmique damping characteristics. To demonstrate the effectiveness of the VAD-damper system for adaptive base-isolation, numerical simulations are conducted for three and seven-story base-isolated buildings subject to both far and near-field ground motions. The results indicate that the system can achieve significant reductions in response compared to the base-isolated buildings with no damper. The proposed system is also found to perform well compared to a typical semi-active damper.  相似文献   

9.
变阻尼半主动结构控制振动台试验   总被引:5,自引:1,他引:4  
在一个1:4的五层模型刚架结构上进行了变阻尼半主动结构控制振动台试验.在结构的底层安装了一个溢流阀式变阻尼控制器,输入几种不同的地震动并采用几种不同的控制算法对结构进行了变阻尼半主动控制。振动台试验结果表明,受阻尼半主动结构控制仅需要很少的电能,就可以达到较好的控制效果,是一种很有应用前景的结构振动控制方案。结合溢流阀式变阻尼控制器的特点,分析了一些因素对控制效果的影响.  相似文献   

10.

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.

  相似文献   

11.
磁流变液是一种性能优良的智能材料,用其制成的MR阻尼器是一种理想的半主动控制装置。本文提出了一种新型MR阻尼器——逆变型MR阻尼器,给出了逆变型MR阻尼器的设计方法,并设计了一个足尺的阀式逆变型MR阻尼器。实验证明逆变型MR阻尼器阻尼力可调,在电源失效或无电源时能够在大阻尼状态工作,这提高了半主动控制装置在地震中的使用安全性。逆变型MR阻尼器具有良好的可靠性、实用性和经济性。本文最后针对试验中阻尼器出力的可调范围比较小的问题给出了几种改进的思路。  相似文献   

12.
带裙房高层建筑地震反应控制振动台试验研究   总被引:1,自引:1,他引:0  
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。  相似文献   

13.
Passive supplemental damping in a seismically isolated structure provides the necessary energy dissipation to limit the isolation system displacement. However, damper forces can become quite large as the passive damping level is increased, resulting in the requirement to transfer large forces at the damper connections to the structure which may be particularly difficult to accommodate in retrofit applications. One method to limit the level of damping force while simultaneously controlling the isolation system displacement is to utilize an intelligent hybrid isolation system containing semi-active dampers in which the damping coeffic ient can be modulated. The effectiveness of such a hybrid seismic isolation system for earthquake hazard mitigation is investigated in this paper. The system is examined through an analytical and computational study of the seismic response of a bridge structure containing a hybrid isolation system consisting of elastomeric bearings and semi-active dampers. Control algorithms for operation of the semi-active dampers are developed based on fuzzy logic control theory. Practical limits on the response of the isolation system are considered and utilized in the evaluation of the control algorithms. The results of the study show that both passive and semi-active hybrid seismic isolation systems consisting of combined base isolation bearings and supplemental energy dissipation devices can be beneficial in reducing the seismic response of structures. These hybrid systems may prevent or significantly reduce structural damage during a seismic event. Furthermore, it is shown that intelligent semi-active seismic isolation systems are capable of controlling the peak deck displacement of bridges, and thus reducing the required length of expansion joints, while simultaneously limiting peak damper forces. Copyright © 1999 John Wiley & Sons, Ltd.  相似文献   

14.
In this paper, a semi-active control by MR-damper is researched; its purpose is to effectively control vibration of asymmetrical cable-stayed bridges when earthquake is loaded on the type of bridge. For an experimental study, a model of 10.2 m high and 28 m long asymmetrical cable-stayed bridge structure was built being similar to a real one in size and function. A MR damper was also designed in proper size suitable for the control of the model. The experiment was performed in the way in which three piers were fixed on three shaking tables with 30% of El-centro earthquake wave, and a control device was placed on the lower part of its upper deck for horizontal control. As for control algorithms, Lyapunov and Clipped-optimal control algorithms were applied. The effectiveness of the semi-active control with MR damper for the asymmetrical cable-stayed bridge was measured under five control conditions: Un-control, Passive-off, Passive-on, Lyapunov Control, Clipped-optimal Control. The experiment showed that the semi-active control applying Lyapunov and Clipped-optimal algorithms effectively increased controllability almost in double, and decreased displacement 75% compared with the condition of passive-off. Therefore the semi-active method suggested in this paper is proven effective in controlling asymmetrical cable-stayed bridges.  相似文献   

15.
多维地震作用下偏心结构的磁流变阻尼器半主动控制   总被引:9,自引:1,他引:8  
理论研究与震害经验表明,地震时结构会产生不可忽略的平动与扭转耦合的空间振动。本文提出了基于线性最优控制理论的部分状态反馈次优控制策略和基于遗传算法的控制策略,以Marlab和Simulink为平台,采用磁流变阻尼器对双向水平地震作用下的偏心结构平.扭耦联反应进行半主动控制。对-6层双向偏心框架结构进行控制效果仿真分析的结果证明,本文提出的2种控制策略是有效的。  相似文献   

16.
基于H∞理论的磁流变阻尼器半主动容错控制   总被引:1,自引:0,他引:1  
建筑结构的半主动控制系统中的传感器,在强震作用下可能因出现故障而影响控制效果。以磁流变阻尼器为例,研究半主动容错控制系统的设计方法。首先,研究了基于状态观测器的半主动H∞控制器设计方法,并将之应用到建筑结构采用磁流变阻尼器的减振控制中;运用改进Bouc-Wen模型,计算磁流变阻尼器的阻尼力,通过求解一个代数Riccati方程和一个状态观测方程,得出了基于状态观测器的H∞主动控制律;再对其采用Clipped-optimal方法实施半主动控制策略。然后,针对传感器故障,利用观测器组的输出残差对故障进行在线诊断,并通过几个观测器状态值的比较得到故障的大小,并据此对传感器的测量值进行修正,从而消除故障对闭环系统的影响,最终实现半主动H∞容错控制。仿真结果表明,该方法具有很好的容错控制效果。  相似文献   

17.
In the field of civil engineering, magnetorheological fluid (MRF) damper-based semi-active control systems have received considerable attention for use in protecting structures from natural hazards such as strong earthquakes and high winds. In this paper, the MRF damper-based semi-active control system is applied to a long-span spatially extended structure and its feasibility is discussed. Meanwhile, a _trust-region method based instantaneous optimal semi-active control algorithm (TIOC) is proposed to improve the performance of the semi-active control system in a multiple damper situation. The proposed TIOC describes the control process as a bounded constraint optimization problem, in which an optimal semi- active control force vector is solved by the trust-region method in every control step to minimize the structural responses. A numerical example of a railway station roof structure installed with MRF-04K dampers is presented. First, a modified Bouc- Wen model is utilized to describe the behavior of the selected MRF-04K damper. Then, two semi-active control systems, including the well-known clipped-optimal controller and the proposed TIOC controller, are considered. Based on the characteristics of the long-span spatially extended structure, the performance of the control system is evaluated under uniform earthquake excitation and travelling-wave excitation with different apparent velocities. The simulation results indicate that the MR fluid damper-based semi-active control systems have the potential to mitigate the responses of full-scale long-span spatially extended structures under earthquake hazards. The superiority of the proposed TIOC controller is demonstrated by comparing its control effectiveness with the clipped-optimal controller for several different cases.  相似文献   

18.
This paper presents the first application of a semi-active damper system to an actual building. The Semi-active Hydraulic Damper (SHD) can produce a maximum damping force of 1000 kN with an electric power of 70 W. It is compact, so a large number of them can be installed in a single building. It is thus possible to control the building's response during a severe earthquake, because a large control force is obtained in comparison with a conventional active control system. This paper outlines the building, the control system configuration, the SHD, the control method using a Linear Quadratic Regulator, the response analysis results of the controlled building, and the dynamic loading test results of the actual SHD. The simulation analysis shows that damage to buildings can be prevented in a severe earthquake by SHD control. The dynamic loading test results of the SHD are reported, which show that the specified design values were obtained in the basic characteristic test. The control performance test using simulated response time histories, also shows that the damping force agrees well with the command. Finally, it is confirmed that the semi-active damper system applied to an actual building effectively controls its response in severe earthquakes. Copyright © 1999 John Wiley & Sons Ltd.  相似文献   

19.
Velocity adjustable TMD and numerical simulation of seismic performance   总被引:2,自引:0,他引:2  
A new type of velocity adjustable tuned mass damper (TMD) consisting of impulse generators and clutches is presented. The force impulse is generated by a joining operation of electromagnets and springs and MR dampers are used as clutches. Rules for velocity adjustment are established according to the working mechanism of TMD. The analysis program is developed on a VB platform. Seismic response of SDOF structures with both passive TMD and velocity adjustable TMD are analyzed. The results show that (1) the control effectiveness of passive TMDs is usually unstable; (2) the control effectiveness of the proposed semi-active TMDs is much better than passive TMDs under typical seismic ground motions; and (3) unlike the passive TMD system, the proposed velocity adjustable TMDs exhibit good control effectiveness even when the primary structure performance becomes inelastic during severe earthquakes.  相似文献   

20.
磁流变阻尼器作为一种比较典型的半主动控制元件,具有构造简单、响应速度快、耐久性好、阻尼力大且连续可调等优点。即使地震中能源中断,磁流变阻尼器仍可以作为被动耗能装置继续工作发挥作用,可靠性高。设计合理有效的磁流变阻尼器半主动控制方法,对于整体结构的减震效果尤其重要。提出一种改进的磁流变阻尼器的半主动控制策略-改进的Bang-Bang控制策略,对装有磁流变阻尼器的减震控制3层框架结构进行了一系列的实时混合模拟试验,对多种半主动控制方法下的振动控制效果进行试验分析。试验结果表明:磁流变阻尼器对框架结构的减震效果显著,并验证了提出的磁流变阻尼器半主动控制策略的有效性。  相似文献   

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