• Title, Summary, Keyword: MR damper

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Performance Evaluation of a Large-scale MR Damper for Controlling Seismic Response using a Real-time Hybrid Test Method (실시간 하이브리드 실험법을 이용한 대형 MR감쇠기의 제진 성능평가)

  • Chung, Hee-San;Lee, Sung-Kyung;Park, Eun-Churn;Youn, Kyung-Jo;Min, Kyung-Won;Lee, Heon-Jae;Choi, Kang-Min;Moon, Suk-Jun;Jung, Hyung-Jo
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.655-660
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    • 2007
  • This paper presents real-time hybrid test method of large-scale MR damper applied to a building structure under seismic excitation. The real-time hybrid test using an actuator for the control performance evaluation of a MR damper controlling the response of earthquake-excited building structure is experimentally implemented. In the test, the building structure is used as a numerical part, on which a large-scale MR damper adopted as an experimental part was installed to reduce its response. At first, the force that is acting between a MR damper and building structure is measured from the load cell attached on the actuator system and is fed-back to the computer to control the motion of the actuator. Then, the actuator is so driven that the error between the interface displacement computed from the numerical building structure with the excitations of earthquake and the fed-back interface force and that measured from the actuator. The control efficiency of the MR damper used in this paper is experimentally confirmed by implementing this process of experiment on real-time.

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Performance Evaluation of a Large-scale MR Damper for Controlling Seismic Responses Using a Real-time Hybrid Test Method (실시간 하이브리드 실험법을 이용한 대형 MR감쇠기의 제진 성능평가)

  • Park, Eun-Churn;Lee, Sung-Kyung;Youn, Kyung-Jo;Chung, Hee-San;Lee, Heon-Jae;Choi, Kang-Min;Moon, Suk-Jun;Jung, Hyung-Jo;Min, Kyung-Won
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.18 no.1
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    • pp.131-138
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    • 2008
  • This paper presents real-time hybrid test method of large-scale MR damper applied to a building structure under seismic excitation. The real-time hybrid test using an actuator for the control performance evaluation of a MR damper controlling the response of earthquake-excited building structure is experimentally implemented. In the test, the building structure is used as a numerical part, on which a large-scale MR damper adopted as an experimental part was installed to reduce its response. At first, the force that is acting between a MR damper and building structure is measured from the load cell attached on the actuator system and is fed-back to the computer to control the motion of the actuator. Then, the actuator is so driven that the error between the interface displacement computed from the numerical building structure with the excitations of earthquake and the fed-back interface force and that measured from the actuator. The control efficiency of the MR damper used in this paper is experimentally confirmed by implementing this process of experiment on real-time.

Decentralized Control of Building Structures Installed with Semi-active MR Damper (준능동 MR 댐퍼가 설치된 건축 구조물의 분산제어)

  • Youn, Kyung-Jo;Lee, Sang-Hyun;Min, Kyung-Won;Lee, Sung-Kyung
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.127-132
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    • 2007
  • In this paper, to overcome local damages of structures, an uncertainty of structural model, installing sensors of structures, and economics of building system, decentralized semi-active magnetorheological(MR) damper using the displacement or velocity transferred to the response of floor installed damper is proposed. Relative magnitude between the control force of dampers and the story shear force is difined as design variables and the performance indices response spectra analysis through nonlinear time history analysis excited by seismic loads is performed according to this design variables. And the performance of this decentralized MR damper is compared with previous centralized LQR control algorithm using 3-stories benchmark building structure excited by El Centro (1940, N.S) in order to evaluate the application of building structures.

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Performance verification of Smart Complex Damping System for Suppressing Vibration of Stay Cable (케이블 진동 저감을 위한 스마트 복합 감쇠 시스템의 성능평가)

  • Park, Chul-Min;Jung, Hyung-Jo;Ko, Man-Gi;Lee, In-Won
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • pp.453-460
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    • 2006
  • Stay cables, such as used in cable-stayed bridges, are prone to vibration due to their low inherent damping characteristics. Recently some studies have shown that active and semiactive control system using MR damper can potentially achieve both higher performance levels than passive control system and adaptability with few of the detractions. However, a control system including a power supply, controller, and sensors is required to maximize the performance of the MR damper and this complicated control system is not effective to most of large civil structures. This paper proposes a smart complex damping system which consists of toggle system and MR dampers by introducing electromagnetic induction(EMI) system as an external power source to MR damper. The performance of the proposed damping device has been compared with that of the passive-type control systems employing a MR damper, a linear viscous damper, and EMI system.

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A Study on The Vibration Reduction of a Driver Seat Controlling an MR Fluid Damper (자기유변유체 댐퍼를 이용한 운전석의 진동감쇠에 대한 연구)

  • 안병일;전도영
    • Journal of Institute of Control, Robotics and Systems
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    • v.8 no.10
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    • pp.861-866
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    • 2002
  • A seat suspension system with a controlled MR(Magneto Rheological) fluid damper is introduced to improve the ride quality and prevent the health risk of a driver compared to fixed seats. The system is located between a seat cushion and the base, and is composed of a spring, MR fluid damper and controller. The MR fluid damper designed in valve mode is capable of producing a wide range of damping force according to applied currents. In experiments, a person was sitting on the controlled seat excited by a hydraulic system The skyhook control, continuous skyhook control and relative displacement control were applied and the continuous skyhook control improved the vibration suppression by 36.6%.

Adaptive MR damper cable control system based on piezoelectric power harvesting

  • Guan, Xinchun;Huang, Yonghu;Li, Hui;Ou, Jinping
    • Smart Structures and Systems
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    • v.10 no.1
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    • pp.33-46
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    • 2012
  • To reduce the vibration of cable-stayed bridges, conventional magnetorheological (MR) damper control system (CMRDS), with separate power supply, sensors and controllers, is widely investigated. In this paper, to improve the reliability and performance of the control system, one adaptive MR damper control system (AMRDS) consisting of MR damper and piezoelectric energy harvester (PEH) is proposed. According to piezoelectric effect, PEH can produce energy for powering MR damper. The energy is proportional to the product of the cable displacement and velocity. Due to the damping force changing with the energy, the new system can be adjustable to reduce the cable vibration. Compared with CMRDS, the new system is structurally simplified, replacing external sensor, power supply and controller with PEH. In the paper, taking the N26 cable of Shandong Binzhou Yellow River Bridge as example, the design method for the whole AMRDS is given, and simple formulas for PEH are derived. To verify the effectiveness of the proposed adaptive control system, the performance is compared with active control case and simple Bang-Bang semi-active control case. It is shown that AMRDS is better than simple Bang-Bang semi-active control case, and still needed to be improved in comparison with active control case.

Semi-active control of smart building-MR damper systems using novel TSK-Inv and max-min algorithms

  • Askari, Mohsen;Li, Jianchun;Samali, Bijan
    • Smart Structures and Systems
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    • v.18 no.5
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    • pp.1005-1028
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    • 2016
  • Two novel semi-active control methods for a seismically excited nonlinear benchmark building equipped with magnetorheological dampers are presented and evaluated in this paper. While a primary controller is designed to estimate the optimal control force of a magnetorheological (MR) damper, the required voltage input for the damper to produce such desired control force is achieved using two different methods. The first technique uses an optimal compact Takagi-Sugeno-Kang (TSK) fuzzy inverse model of MR damper to predict the required voltage to actuate the MR dampers (TSKFInv). The other voltage regulator introduced here works based on the maximum and minimum capacities of MR damper at each time-step (MaxMin). Both semi-active algorithms developed here, use acceleration feedback only. The results demonstrate that both TSKFInv and MaxMin algorithms are quite effective in seismic response reduction for wide range of motions from moderate to severe seismic events, compared with the passive systems and performs better than original and Modified clipped optimal controller systems, known as COC and MCOC.

Multi-mode cable vibration control using MR damper based on nonlinear modeling

  • Huang, H.W.;Liu, T.T.;Sun, L.M.
    • Smart Structures and Systems
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    • v.23 no.6
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    • pp.565-577
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    • 2019
  • One of the most effective countermeasures for mitigating cable vibration is to install mechanical dampers near the anchorage of the cable. Most of the dampers used in the field are so-called passive dampers where their parameters cannot be changed once designed. The parameters of passive dampers are usually determined based on the optimal damper force obtained from the universal design curve for linear dampers, which will provide a maximum additional damping for the cable. As the optimal damper force is chosen based on a predetermined principal vibration mode, passive dampers will be most effective if cable undergoes single-mode vibration where the vibration mode is the same as the principal mode used in the design. However, in the actual engineering practice, multi-mode vibrations are often observed for cables. Therefore, it is desirable to have dampers that can suppress different modes of cable vibrations simultaneously. In this paper, MR dampers are proposed for controlling multi-mode cable vibrations, because of its ability to change parameters and its adaptability of active control without inquiring large power resources. Although the highly nonlinear feature of the MR material leads to a relatively complex representation of its mathematical model, effective control strategies can still be derived for suppressing multi-mode cable vibrations based on nonlinear modelling, as proposed in this paper. Firstly, the nonlinear Bouc-wen model is employed to accurately portray the salient characteristics of the MR damper. Then, the desired optimal damper force is determined from the universal design curve of friction dampers. Finally, the input voltage (current) of MR damper corresponding to the desired optimal damper force is calculated from the nonlinear Bouc-wen model of the damper using a piecewise linear interpolation scheme. Numerical simulations are carried out to validate the effectiveness of the proposed control algorithm for mitigating multi-mode cable vibrations induced by different external excitations.

Opposition based charged system search for parameter identification problem in a simplified Bouc-Wen model

  • Shirgir, Sina;Azar, Bahman Farahmand;Hadidi, Ali
    • Earthquakes and Structures
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    • v.18 no.4
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    • pp.493-506
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    • 2020
  • In this paper, a new opposition based charged system search (CSS) is proposed to be used as a parameter identification of highly nonlinear semi-active magneto-rheological damper. By replacing the opposition particles with current solutions, the mentioned strategy is used to enhance the search space and to increase the exploration of CSS. To investigate the effectiveness of the proposed method, a nonlinear modified Bouc-Wen model of MR damper is considered to find its parameters, and compare it with those achieved from experimental model of MR damper. Also, by exploiting the sensitivity analysis and using the importance vector, the less importance parameters in the Bouc-Wen model are eliminated which makes the MR damper model simpler. Results demonstrate the new proposed algorithm (OBLCSS) has a high ability to tackle highly nonlinear problems. Based on the results of the α importance vector, a simplified model is proposed and its parameters are identified by using the presented OBLCSS algorithm. The simplified proposed model also has a high capability of estimating damper responses.