• 제목, 요약, 키워드: MR damper

검색결과 370건 처리시간 0.031초

부가적인 유로가 있는 MR 댐퍼의 감쇠력 특성 (Damping Force Characteristics of MR Damper with Additional Flow Path)

  • 손정우;오종석;최승복
    • 한국소음진동공학회논문집
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    • v.25 no.6
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    • pp.426-431
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    • 2015
  • In this work, a new type of MR damper with additional flow path in piston is proposed and damping force characteristics are numerically evaluated. Flow-mode type MR damper is considered and mathematical model is established based on Bingham rheological model of MR fluid to obtain accurate prediction of damping force characteristics. Damping force of the proposed MR damper are calculated with respect to piston velocity and input current. In addition, investigation on damping force characteristics is carried out according to number of additional flow path and excellence of the proposed MR damper is demonstrated.

구조물의 진동제어를 위한 MR-damper의 최적 제어력 산정 (Calculating a MR Damper's Optimal Capacity for a Control of Structural Vibration)

  • 허광희;전승곤;김충길;전준용;이진옥;서상구
    • 한국지진공학회논문집
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    • v.20 no.3
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    • pp.163-169
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    • 2016
  • In the case where a MR-damper is employed for vibration control, it is important to decide on how much control capacity should be assigned to it against structural capacities (strength and load, etc). This paper aims to present a MR-damper's control capacity suitable for the capacities of the structure which needs to be controlled. First, a two span bridge was built equipped with a MR-damper, which constitutes a two-span MR-damper control system. Then, inflicting an earthquake load on the system, a basic experiment was performed for vibration control, and a simulation was also carried out reflecting specific control conditions such as MR-damper and rubber bearing. The comparison of the results against each other proved their validity. Then, in order to calculate an optimal control capacity of the MR-damper, structural capacity was divided into eleven cases in total and simulated. For each case, an additional load of 30 KN was inflicted everytime, thereby increasingly strengthening structural capacity. As a result of the study, it was found that the control capacity of MR-damper of 30 KN was safely secured only with lumped mass of more than 150 KN(case 6). Therefore, it is concluded the MR-damper showed the best performance of control when it exerted its capacity at around 20% of structural capacity.

Herschel-Bulkley 모델을 이용한 MR 댐퍼 승용차의 제어 성능 고찰 (Control Performance Investigation of MR Fluid Damper using Herschel-Bulkley Shear Model)

  • 이덕영;황우석
    • 한국소음진동공학회:학술대회논문집
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    • pp.323-328
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    • 2002
  • The control performance of a vehicle installed with an MR(magnetorheological) fluid-based damper is investigated on the basis of Herschel-Bulkley shear model. Generally, most of MR fluid damper has been analyzed based on a simple Bingham-plastic shear model. However, the Bingham-plastic shear model can not well describe the behavior of the damper on the condition of high velocity and high current field input. Therefore, in this study, the Herschel-Bulkley shear model in which the constant post-yield plastic viscosity in Bingham model is replaced with a power law model dependent on shear rate is used to assess control performance of a vehicle with MR fluid damper suspension system. This study deals with a two-degree-of-freedom suspension using the MR fluid damper for a quarter car model. The response for the bump input to identify the fastness of MR fluid damper embedded skyhook controller and requested magnetic field are investigated.

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MR댐퍼 기반의 스마트 수동제어 시스템 (Smart Passive System Based on MR Damper)

  • 조상원;조지성;김춘호;이인원
    • 한국지진공학회논문집
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    • v.9 no.1
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    • pp.51-59
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    • 2005
  • 본 연구에서는 위의 어려움을 해결하기 위해, 스마트 수동제어 시스템을 제안하였다. 스마트 수동제어 시스템은 MR댐퍼와 EMI시스템으로 구성되며, EMI시스템은 영구자석과 솔레노이드 코일로 이루어진다. EMI시스템은 MR댐퍼의 왕복운동에너지를 전기에너지로 변환하므로, 스마트 수동제어 시스템은 외부 전원 없이 외부하중에 따라 댐퍼의 점성을 바꾸는 적응성을 갖는다. 따라서 간단하고 효율적인 장치로써, 대형토목구조물에 적용 가능하다. 이의 확인을 위해 예제를 통한 수치해석을 수행하였으며, 스마트 수동제어 시스템이 강진에 대해서는 기존의 반능동 제어 MR댐퍼 시스템 보다 우수한 성능을 보인다.

MR 시트댐퍼를 장착한 상용차의 제어성능 평가 (Performance Evaluation of Commercial Vehicle with MR Seat Damper)

  • 성금길;이호근;남무호;최승복
    • 한국소음진동공학회:학술대회논문집
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    • pp.1048-1053
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    • 2003
  • This paper proposed a MR(Magneto-rheological) seat damper for a commercial vehicle. After formulating the governing equation of motion, an appropriate size of damper is designed and manufactured. Following the equation of fie d-dependent damping force characteristics, a semi-active seat suspension installed with the proposed MR-damper is constructed and its dynamic model id established, Subsequently, vibration isolation performance of the semi-active suspension system is demonstrated by incorporating with a MRAC(Model referenced adaptive control) fer the MR Seat Damper

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Magneto-rheological and passive damper combinations for seismic mitigation of building structures

  • Karunaratne, Nivithigala P.K.V.;Thambiratnam, David P.;Perera, Nimal J.
    • Earthquakes and Structures
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    • v.11 no.6
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    • pp.1001-1025
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    • 2016
  • Building structures generally have inherent low damping capability and hence are vulnerable to seismic excitations. Control devices therefore play a useful role in providing safety to building structures subject to seismic events. In recent years semi-active dampers have gained considerable attention as structural control devices in the building construction industry. Magneto-rheological (MR) damper, a type of semi-active damper has proven to be effective in seismic mitigation of building structures. MR dampers contain a controllable MR fluid whose rheological properties vary rapidly with the applied magnetic field. Although some research has been carried out on the use of MR dampers in building structures, optimal design of MR damper and combined use of MR and passive dampers for real scale buildings has hardly been investigated. This paper investigates the use of MR dampers and incorporating MR-passive damper combinations in building structures in order to achieve acceptable levels of seismic performance. In order to do so, it first develops the MR damper model by integrating control algorithms commonly used in MR damper modelling. The developed MR damper is then integrated in to the seismically excited structure as a time domain function. Linear and nonlinear structure models are evaluated in real time scenarios. Analyses are conducted to investigate the influence of location and number of devices on the seismic performance of the building structure. The findings of this paper provide information towards the design and construction of earthquake safe buildings with optimally employed MR dampers and MR-passive damper combinations.

지진특성에 따른 MR 감쇠기가 설치된 단자유도 구조물의 등가감쇠비 (Equivalent damping ratio based on earthquake characteristics of a SDOF structure with an MR damper)

  • 문병욱;박지훈;이성경;민경원
    • 한국소음진동공학회:학술대회논문집
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    • pp.459-464
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    • 2007
  • Seismic control performance of MR dampers, which have severe nonlinearity, differs with respect to the dynamic characteristics of an earthquake such as magnitude, frequency and duration. In this study, the effects of excitation characteristics on the equivalent linear system of a building structure with the MR damper are investigated through numerical analysis for artificial ground motions generated from different response spectrums. The equivalent damping ratio of the structure with the MR damper is calculated using Newmark and Hall's equations for ground motion amplification factors. It is found that the equivalent damping ratio of the structure with the MR damper is dependent on the ratio of the maximum friction force of the MR damper over excitation magnitude. Frequency contents of the earthquake ground motion affects the equivalent damping ratio of long-period structures considerably. Also, additional damping effect caused by interaction between the viscousity and friction of the MR damper is observed. Finally, response reduction factors for equivalent linear systems are proposed in order to improve accuracy in the prediction of the actual nonlinear response.

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MR 감쇠기가 설치된 단자유도 구조물의 지진응답에 기초한 등가감쇠비 (Equivalent damping ratio based on the earthquake response of a SDOF structure with a MR damper)

  • 박지훈;문병욱;민경원
    • 한국소음진동공학회:학술대회논문집
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    • pp.879-885
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    • 2006
  • Seismic control performance of MR dampers, which have severe nonlinearity, differs with respect to the dynamic characteristics of an earthquake such as magnitude, frequency and duration. In this study, the effects of excitation characteristics on the equivalent linear system of a building structure with the MR damper are investigated through numerical analysis for artificial ground motions generated from different response spectrums. The equivalent damping ratio of the structure with the MR damper is calculated using Newmark and Hall's equations for ground motion amplification factors. It is found that the equivalent damping ratio of the structure with the MR damper is dependent on the ratio of the maximum friction force of the MR damper over excitation magnitude. frequency contents of the earthquake ground motion affects the equivalent damping ratio of long-period structures considerably. Also, additional damping effect caused by interaction between the viscousity and friction of the MR damper is observed. Finally, response reduction factors for equivalent linear systems are proposed in order to improve accuracy in the prediction of the actual nonlinear response.

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지진특성에 따른 MR감쇠기가 설치된 단자유도 구조물의 등가감쇠비 (Equivalent Damping Ratio Based on Earthquake Characteristics of a SDOF Structure with an MR Damper)

  • 문병욱;박지훈;이성경;민경원
    • 한국소음진동공학회논문집
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    • v.18 no.1
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    • pp.87-93
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    • 2008
  • Seismic control performance of MR dampers, which have severe nonlinearity, varies with respect to the dynamic characteristics of an earthquake such as magnitude, frequency and duration. In this study, the effects of excitation characteristics on the equivalent linear system of a building structure with the MR damper are investigated through numerical analysis for artificial ground motions generated from different response spectrums. The equivalent damping ratio of the structure with the MR damper is calculated using Newmark and Hall's equations for ground motion amplification factors. It is found that the equivalent damping ratio of the structure with the MR damper is dependent on the ratio of the maximum friction force of the MR damper over excitation magnitude. Frequency contents of the earthquake ground motion affects the equivalent damping ratio of long-period structures considerably. Also, additional damping effect caused by interaction between the viscousity and friction of the MR damper is observed. Finally. response reduction factors for equivalent linear systems are proposed in order to improve accuracy in the prediction of the actual nonlinear response.