• 소음진동
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• 제8권3호
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• pp.457-466
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• 1998

This paper evaluates the performance of a Magneto-Rheological (MR) fluid mount. The mount incorporates MR fluid in a conventional fluid mount to open and closed the inertia track between the fluid chambers of the mount. It is shown that such switching of the inertia track improves the mount's isolation effect, by eliminating the large transmissibility peak that commonly exists at frequencies higher than the notch frequency for conventional fluid mounts. The switching frequencies of the MR mount is evaluated, based on the parameters of the mount. A simple control scheme for switching the mount between the open and closed states is proposed, and the performance of the controlled mount is compared with conventional mounts. A sensitivity analysis is conducted to evaluate the effect of parameter errors in estimating the switching frequencies and mount performance. The results show that the switching frequencies can be accurately determined from mount parameters that are easily measured or estimated.

• 한국산학기술학회논문지
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• 제9권6호
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• pp.1511-1517
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• 2008

외부에서 인가되는 전류의 세기에 따라 결합력의 세기가 달라지는 자기점성유체의 특성을 이용한 자기점성 유체 댐퍼는 유체의 결합력을 통해 전단력을 발생시켜 진동의 제어가 가능하다. 자기점성유체 댐퍼의 성능을 좌우 하는 코일 작동부의 최적화를 위해 유한요소해석을 이용해 코일 형상에 따른 전자기력의 성능비교를 실시하였다. 또한 고효율 댐퍼를 제작하기 위한 방법으로 다단의 코일 작동부를 가지는 댐퍼를 제안하였으며, 기존의 댐퍼와의 전자기적 성능 비교를 통해 댐퍼의 성능 비교를 수행하고 제한된 조건에서 최대의 효과를 가질 수 있는 방안을 제시하고 그에 따른 전자기장 해석을 수행하였다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문초록집
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• pp.328.1-328
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• 2002

MR(Magneto-rheological) fluid is smart fluid that can change its characteristics when magnetic fields are applied. Recently, many researches are going on this MR fluid for the application in a variety of areas including automobile shock absorbers. This paper describes the design procedure of a MR damper and the analysis results of its dynamic characteristics. MR fluid in the magnetic field shows initial yield shear stress and increasing resistive viscousity with final saturation thereafter. (omitted)

• 유공압시스템학회논문집
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• 제1권1호
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• pp.17-22
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• 2004

The goal of this paper is to improve the position control performance of pneumatic rotary actuator with variable brake using Magneto-Rheological Fluid. The air compressibility and the lack of damping of the pneumatic actuator bring the dynamic delay of the pressure response and cause the oscillatory motion. In this study, a variable rotary brake comprising Magneto-Rheological Fluid is equipped to the joint of a pneumatic manipulator. Experiments of step response have proved that the transient response of the manipulator could be improved compared with that of the conventional control algorithm by using a phase plane switching control algorithm.

• 한국소음진동공학회논문집
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• 제14권6호
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• pp.470-477
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• 2004

This study shows the design process of a MR damper for semi-active suspension systems. Damping force characteristics of the designed damper was predicted through the flow analysis and magnetic analysis. The predicted results were compared with the experimental results and the initial design specification was modified according to the results.

• Korea-Australia Rheology Journal
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• 제18권3호
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• pp.121-126
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• 2006

A carbonyl iron-based magneto-rheological suspension was compressed in the direction of the applied magnetic field and the change in rheological properties was measured. It was found that the compression did not have a large effect on the magneto-rheological response, which is in contrast to recent reports in the literature describing an almost order of magnitude increase in the shear yield stress. The difference can be attributed to the latter test's use of a sliding wedge apparatus which imparts considerable shearing to the sample during the compression.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문집
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• pp.187-189
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• 2002

This paper presents property of the squeeze mode type mount using Magneto-Rheological fluid(MR fluid). The mount can isolate multi-directional vibrations, and also effectively reduce the vibrations in a wide range of disturbance frequencies by controlling the applied magnetic field. The shape of the mount is the same that of squeeze film damper. In the present work, the performance of this mount was experimentally investigated according to changing the magnetic field strength.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 D
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• pp.2962-2964
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• 2005

Magneto-Rheological (MR) fluid is suspension of fine magnetic particles in a liquid carrier such as silicon oil or water. MR fluid exhibits solid-like mechanical behavior into chain or clusters with high yield stress when magnetic field is applied to the particles. The response of MR fluids is very quick and reversible after removal of the field. MR Fluids have high yield stress (up to 5kPs) and operate in low voltage power supply. Recently, MR damper using MR fluids was open used in vibration control system such as structural devices, seat vibration controllers and helicopter rotor systems, but it is too big in size and heavy. Therefore, it is not appreciate to rehabilitation devices such as prosthetic limbs.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문초록집
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• pp.325.1-325
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• 2002

This paper presents property of the squeeze mode type mount using Magneto-Rheological fluid (MR fluid). The mount can isolate multi-directional vibrations, and also effectively reduce the vibrations in a wide range of disturbance frequency by controling the applied magnetic field. The shape of the mount is the same that of squeeze film damper. In the present work, the performance of this mount was experimentally investigated according to changing the magnetic field strength. (omitted)

• 한국소음진동공학회논문집
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• 제13권7호
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• pp.517-523
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• 2003

This paper presents response property of the squeeze mode type mount using Magneto-Rheological fluid (MR fluid) . The MR mount for the isolation of multi-directional vibrations was constructed in this study. Both the mechanism and shape of the mount are the same as squeeze film dampers for a rotor system. In the present work, the performance of the mount was experimentally Investigated according to the magnetic field strength. The experimental results present that the MR mount can effectively reduce the vibration in a wide range of frequency by controlling the applied electromagnetic filed strength. Viscous damping and stiffness coefficients of the MR mount tend to be changed according to the variation of the applied currents In this study.