• Journal of Power System Engineering
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• v.8 no.2
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• pp.53-58
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• 2004

In this paper, the semi active mount featuring Magneto rheological fluid(MR Fluid) is proposed. MR fluid is suspension of micro sized magnetizable particles in a fluid medium, and its apparent viscosity can be varied by the applied strength of magnetic field. When the controllable MR fluid is applied to mechanical devices, the devices provide simple, rapid response interfaces between electronic controls and mechanical systems. The MR fluid is applied in the conventional fluid mount for improving its performance of the mount's isolation effect. A appropriate size of the MR mount is designed and manufactured on the basis of Bingham model of MR fluid. In addition, the field dependent damping forces of MR mount are evaluated with respect to the input frequency variation.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.3 no.1
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• pp.84-89
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• 2004

This study is a basic one for application of ER Fluid to fluid power systems. By mixing silicone oil with zeolite particles, four kinds of ER fluids were made, in which the weight ratio of zeolite particles are different. We examined how the Yield shear stress and Bingham characteristics of the ER fluids are effected by varying electric field intensity. We designed and constructed a disk type power transmission clutch in which ER fluid fills and this ER fluid transmits the power of drive shaft to the driven shaft. With this equipment, the revolution transmission ratio from the chive shaft to the driven shaft by varying electric field density of the ER fluid was examined.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1994.06b
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• pp.19-29
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• 1994

Since Winslow (1) has reported an electro - theological (ER) effect which features remarkable and reversible changes in the properties of the fluid due to an imposed external electric field, numerous applications of ER fluids in mechanical devices, such as clutches, control valves, active dampers, and etc. have been proposed to improye dramatical ly their performances (2,3). When the external electric field is imposed to the ER fluid, it behaves as a Bingham fluid, displaying a field dependent yield shear stress which is widely variable. Without the electric field, the ER fluid has a reversible and constant viscosity so that it flows as a Newtonian fluid. Another salient feature of the ER fluid is that the time required for the variation is very short (< 0.001 sec) (4-6). These attractive.characteristics of the ER fluid provide the possibility of the appearance of new engineering technology , for instance, an active vibration control system. Recently, the application of the ER fluid to rotor-bearing systems has been also initiated.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.19 no.7
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• pp.659-666
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• 2009

This paper proposes a new method for dynamic modeling of electrorheological(ER) damper considering fluid compressibility. After describing configuration and operating principle of the ER damper, a quasi-static modeling of the ER damper is conducted on the basis of Bingham model of ER fluid. Subsequently, the dynamic model for describing the ER damper considering compressibility of ER fluid and gas chamber is obtained using the lumped parameter method. This method includes dynamic motions of annular duct, upper chamber, lower chamber and connecting pipe. The hysteresis behavior of the ER damper is evaluated through computer simulations and compared with experimental results. In addition, the hysteresis behavior due to the compressibility of ER fluid and gas chamber is investigated through computer simulations.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2009.04a
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• pp.438-443
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• 2009

This paper proposes a new method for dynamic modeling of electrorheological (ER) damper considering fluid compressibility. After describing configuration and operating principle of the ER damper, a quasi-static modeling of the ER damper is conducted on the basis of Bingham model of ER fluid. Subsequently, the dynamic model for describing the ER damper considering compressibility of ER fluid and gas chamber is obtained using the lumped parameter method. This method includes dynamic motions of annular duct, upper chamber, lower chamber and connecting pipe. The hysteresis behavior of the ER damper is evaluated through computer simulations and compared with experimental results. In addition, the hysteresis behavior due to the compressibility of ER fluid and gas chamber is investigated through computer simulations.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.14 no.5
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• pp.49-54
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• 2005

An experimental Investigation was performed to study the characteristics of Electro-Rheological fluid flow in a horizontal rectangular tube with or without D.C electric field control. First, the microscopic behavior of the ER suspension structure between rectangular tube brass electrodes for the stationary ER nut(i and flow of the ER fluid was investigated by flow visualization. The flow of the ER fluid between fluid rectangular tube was solved experimental using the constitutive equation for a Bingham fluid. ER fluid is made silicon oil mixed with $0.2wt\%$ starch having hydrous particles. Velocity distributions of the ER fluids were obtained by particle image velocimetry measuring those of the clusters using an image processing technique.

• KSTLE International Journal
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• v.8 no.1
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• pp.7-10
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• 2007

The rheological property of hollow PANI malonate suspension in silicone oil was investigated by varying the electric fields and shear rates, respectively. The hollow PANI malonate susepnsion showed a typical electrorheological (ER) response caused by the polarizability of an amide polar group and shear yield stress due to the formation of chains upon application of an electric field. The shear stress for the hollow PANI malonate suspension exhibited an electric field power of 0.90. On the basis of the experimental results, the newly synthesized hollow PANI malonate suspension was found to be an anhydrous ER fluid.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.775-778
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• 2000

Magnetorheological Finishing(MRF) is a newly developed and recently commercialized for finishing optical components. The magnetorheological fluid consists of a water based suspension of carbonyl iron, nonmagnetic polishing abrasives, and small amounts of stabilizer. Theoretical analysis of MRF, based on Bingham lubrication theory, is illustrated and a correlation between surface shear stress on the workpiece and material removal is obtained.

• Journal of the Korean Society for Precision Engineering
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• v.18 no.9
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• pp.45-52
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• 2001

This paper presents two different models of electrorheological(ER) valves which can be applicable to an automatic cargo handling system at the seaport. Four different ER fluids, which are commercially available, are adopted and their Bingham characteristics are experimentally evaluated with respect to the intensity of electric field. The field-dependent Bingham models are used in the design of two types of ER valves; single-type and divided-type. The governing equations of motion of the ER valves are derived and the principal design parameters are determined based on 200ton platform to be vertically controlled by the ER valves. Both pressure drops due to the applied field and current density required to operate the ER valves are analyzed. In addition, the pressure drops of the cylinder system are evaluated for both ER valves.

• Journal of the Earthquake Engineering Society of Korea
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• v.23 no.4
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• pp.211-219
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• 2019

In this study, SMG(Smart Material with Grease) was developed, which was improved the precipitation minute particle in grease during long term standstill. Also, small-sized cylinder damper equipped with an electromagnet in a piston was developed for using a performance evaluation of the damper with SMG and the dynamic load test, and damping force using Power model and Bingham model was derived in order to compare to the result of that of the damper. The data obtained from the dynamic load test were analyzed and plotted, and then a dynamic range was calculated to evaluate the usability of the damper with SMG. The performance of the damper with SMG was compared to the damping forse derived from the Power and Bingham model. The result of this evaluation shown that the usability of SMG damper was demonstrated by this test as a semi-active controlling equipment of small-sized damper.