• Title/Summary/Keyword: ER FLUID

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Vibration Control of a Drive Feeding System Using ER CD-ROM Mounts (ER CD-ROM 마운트를 이용한 드라이브 피딩 시스템의 진동 제어)

  • 최승복;김형규;임수철;박영필
    • Journal of KSNVE
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    • v.9 no.6
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    • pp.1247-1258
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    • 1999
  • This paper presents vibration control of a CD-ROM(compact disc-read only memory) drive feeding system consisting of a new type of CD-ROM mount using an electro-rheologocal(ER) fluid. Chemically treated starch particles and silicon oil are used for EF fluid, and its field-dependent yield stresses are experimentally distilled under both the shear and the flow modes. On the basis of the yield stress, an appropriate size of ER CD-ROM mount adapted to conventional feeding system is designed and manufactured. Vibration isolation performance of the proposed mount is evaluated in the frequency domain and compared with that of conventional rubber mount. The ER CD-ROM mount is then installed to the drive feeding system and the system equation of motion is derived. The skyhook controller is then incorporated with the fuzzy technique to improve the performance of ER CD-ROM mount. A set of fuzzy parameters and control rules are obtained from a relation between vertical displacement and pitching motion of the feedng system. Followingthe formulation of the fuzzy-skyhook controller, computer simulation is undertaken in order to evaluate vibration suppression of the CD-ROM drive feeding system subjected to various excitations.

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Electrorheology of Hollow Polyaniline Pimelate Suspension by Conduction Model

  • Choi Ung-Su
    • KSTLE International Journal
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    • v.7 no.1
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    • pp.1-4
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    • 2006
  • The electro rheological behavior of the hollow polyaniline pimelate suspension in silicone oil was investigated. Hollow polyaniline pimelate suspension showed a typical ER response (Bingham flow behavior) upon application of an electric field. The shear stress for the suspension exhibited the dependence with a factor equals to 0.84 power on the electric field. The experimental results for the hollow polyaniline pimelate suspension correlated with the conduction models of Tang et al., and this suspension behaved as an ER fluid.

Electrorheological Properties of Cellulose Phosphate Ester Suspension by Conduction Models (전도성 모델에 의한 인산에스테르셀룰로오즈 현탁액의 전기유변학적 특성 연구)

  • 최웅수;고영건;박용성;권오관
    • Tribology and Lubricants
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    • v.17 no.2
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    • pp.124-129
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    • 2001
  • The electrical and rheological behaviors of the cellulose phosphate ester suspension in the silicone oil were investigated. Cellulose phosphate ester suspension showed a typical ER response (Bingham flow behavior) upon application of an electric field. The shear stress for the cellulose phosphate ester suspension exhibited a linear dependence on the volume fraction of particles and a square power of the electric field. On the basis of the experimental results, cellulose phosphate ester suspension correlated with the conduction model of Tang et al, and found to be an ER fluid.

Rheology of Hollow Polyaniline Gutarate Suspension Under DC Electric Field

  • Choi, Ung-Su
    • KSTLE International Journal
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    • v.9 no.1_2
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    • pp.36-38
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    • 2008
  • The electrical and rheological behavior of the hollow polyaniline glutarate suspension in silicone oil was investigated. Hollow polyaniline glutarate suspension showed a typical ER response (Bingham flow behavior) under a DC electric field. The shear stress for the suspension exhibited the dependence with a factor equals to 0.95 power on the electric field. The experimental results for the hollow polyaniline glutarate suspension behaved as an ER fluid.

Electrical and Rheological Properties of Chitosan Malonate Suspension

  • Choi, Ung-su
    • KSTLE International Journal
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    • v.4 no.1
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    • pp.14-17
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    • 2003
  • The electrical and rheological properties of a chitosan malonate suspension in silicone oil was investigated by varying the electric fields, volume fractions of particles, and shear rates, respectively, The chitosan 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 multiple chains upon application of an electric field. The shear stress fur the suspension exhibited a linear dependence on the volume fraction and an electric field power of 1.88. On the basis of the experimental results, the newly synthesized chitosan malonate suspension was found to be an anhydrous ER fluid.

Characteristics of ERF Polishing using Chemical-oil (케미컬오일을 이용한 ERF 연마 특성)

  • 윤종호;이재종;이응숙;이동주;김영호
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2004.04a
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    • pp.27-33
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    • 2004
  • Electro-theological fluid is recently used for the micro polishing of 3-dimensional micro-aspherical lens. It's also used for polishing small area defects on the wide flat wafer. Since ER fluid shows a behavior of viscosity changing under certain electric fields. micro polishing efficiency may be enhanced for certain cases. In this paper, a perfluorinated carbonyl fluoride oil based ER fluids was used to improve surface polishing rate and submicron-scale accuracy. As the polishing electrodes, micro size cylindrical tools had been used for maximizing the electric field. An experimental device, which was applied for micro polishing a number of wafers of 4inches in size and other workpiece. was made on a precision polishing system. It consisted of a steel electrode. a wafer fixture. l0㎃ current and DC 5㎸ power supply unit, and a controller unit. From the Experiments. the ER fluid is applicable for micro polishing of small parts.

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Maneuver Analysis of Full-Vehicle Featuring Electrorheological Suspension and Electrorheological Brake (ER 현가장치 및 ER 브레이크를 적용한 전체차량의 거동분석)

  • Sung, Kum-Gil;Choi, Seung-Bok
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2007.05a
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    • pp.1125-1130
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    • 2007
  • This paper presents a maneuver analysis of a full-vehicle featuring electrorheological (ER) suspension and ER brake. In order to achieve this goal, an ER damper and an ER valve pressure modulator are devised to construct ER suspension and ER brake systems, respectively. After formulating the governing equations of the ER damper and ER valve pressure modulator, they are designed and manufactured for a middle-sized passenger vehicle, and their field-dependent characteristics are experimentally evaluated. The governing equation of motion for the full-vehicle is then established and integrated with the governing equations of the ER suspension and ER brake. Subsequently, a sky-hook controller for the ER suspension and a sliding mode controller for the ER brake are formulated and implemented. Control performances such as vertical displacement and braking distance of vehicle are evaluated under various driving conditions through computer simulations.

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Ride Comfort Analysis of Passenger Vehicle Featuring ER Damper with Different Tire Pressure (타이어 공기압에 따른 ER 댐퍼 장착 승용차의 승차감분석)

  • Sung, Kum-Gil;Choi, Seung-Bok
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.26 no.2
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    • pp.210-216
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    • 2016
  • In this work, performance analysis to improve ride comfort of an ER (electrorheological) fluid damper for a mid-sized passenger vehicle in terms of tire pressure is presented. An ER damper by considering specification for a mid-sized commercial passenger vehicle is proposed and mechanically designed. After manufacturing and assembling the proposed ER damper with design parameters, their performance such as field-dependent damping forces are experimentally measured. A quarter-vehicle ER ECS (Electronic Control Suspension) system consisting of the ER damper, sprung mass, spring, sky-hook controller and tire is constructed to analysis the ride comfort performances. Vertical tire stiffness with different tire pressure is experimentally measured and investigated. In addition, ride comfort analysis such as vertical acceleration root mean square (RMS) of sprung mass is investigated under bump road using quarter-vehicle test equipment.

Role of surfactant on damping performance of polyaniline based electrorheological suspension

  • Kim, Ji-Woo;Kim, Chul-Am;Choi, Hyoung-Jin;Choi, Seung-Bok
    • Korea-Australia Rheology Journal
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    • v.18 no.1
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    • pp.25-30
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    • 2006
  • To enhance the stability of dispersed polyaniline (PANI) particles in a silicone oil system, a nonionic surfactant was adopted, and its effect on the electrorheological (ER) performance was investigated under an applied electric field. In the presence of a nonionic surfactant, the PANI based ER fluid exhibited not only an improved sedimentation stability based on the estimated sedimentation ratio but also an enhanced maximum yield stress behavior. Furthermore, the surfactant added ER suspension was applied to an ER damper system, and its damping performance was compared with the ER suspension without a surfactant.