• Title/Summary/Keyword: Anisotropic Magneto-rheological Elastomer

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The Variation Rate of Shear Modulus for Anisotropic Magneto-rheological Elastomer due to Volume Fraction of CIP (CIP 부피비에 따른 이방성 MRE의 전단계수 변화율)

  • Jeong, Un-Chang;Yoon, Ji-Hyun;Yang, In-Hyung;Lee, You-Yub;Oh, Jae-Eung
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.21 no.12
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    • pp.1132-1137
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    • 2011
  • MRE(magneto-rheological elastomers) is a material which shows reversible and various modulus in magnetic field. Comparing to conventional rubber vibration isolator, MREs are able to absorb vibration of broader frequency range. These characteristic phenomena result from the orientation of magnetic particles named carbonyl iron powder(CIP) in rubber matrix. In this paper, simulation on variation rate of shear modulus for anisotropic MRE due to volume fraction of CIP and an effective permeability model was applied to predict the field-induced shear modulus of MREs. Also, the variation rate of shear modulus for anisotropic MRE was derived using magneto-mechanical theory. Based on Maxwell-Garnett mixing rule, the increment of shear modulus was calculated to evaluate the shear modulus of MREs with column structure of CIP due to induced current. The simulation results on variation rate of shear modulus can be applied to the variable mechanical system of MRE such as tunable vibration absorber, stiffness variable bush and mount.

Effect of Precured EPDM on the Property of Magneto-rheological Elastomer Based on NR/EPDM Blend

  • Na, Bokgyun;Chung, Kyungho
    • Elastomers and Composites
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    • v.53 no.2
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    • pp.67-74
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    • 2018
  • Magneto-rheological elastomers (MREs) are smart materials in which the inherent stiffness and damping properties can be changed by the influence of an external magnetic field. The magneto-rheological (MR) effect depends on the orientation characteristics of the dispersed magneto-responsible particles (MRPs) in the matrix. In this study, natural rubber (NR) and ethylene propylene diene rubber (EPDM) were blended and used as a matrix of an MRE. EPDM was pre-cured before blending with NR. The Mooney viscosity, curing characteristics, and mechanical properties were analyzed with various pre-curing conditions of EPDM and the NR/EPDM blend. The results show that excellent mechanical properties of the NR/EPDM blend-based MRE were obtained when the pre-curing time of EPDM was 60 min. The aging property of the NR-based MRE was improved by the introduction of pre-cured EPDM. Also, the anisotropic MRE showed a higher MR effect than that of the isotropic MRE.

The Effect of Orientation of Magneto-responsible Particles on the Transmissibility of Magneto-rheological Elastomer (자기장 응답 입자의 배향이 자기유변 탄성체의 전달성에 미치는 영향)

  • Lee, Joo-Hwan;Chung, Kyung-Ho;Yoon, Ji-Hyun;Oh, Jae-Eung;Kim, Min-Soo;Yang, Kyung-Mo;Lee, Seong-Hoon
    • Elastomers and Composites
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    • v.46 no.4
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    • pp.311-317
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    • 2011
  • The neodymium magnet inserted mold was proposed to orient magneto-responsible particles efficiently. The anisotropic magneto-rheological elastomer(MRE) was prepared using the new mold and the optimum amounts of the particles was 30 vol.%. As the orientation of particles was increased, the tensile strength of MRE was decreased, while the hardness of MRE was increased. It was found that the MRE containing 30 vol.% of magneto-responsible particles showed the maximum magneto-rheological effect. The ratio of shear modulus shift was 59% at the input current of 3 A. The transmissibility of MRE was decreased with increasing the input current and loading amounts of magneto-responsible particles. Therefore, the damping property of MRE could be improved by preparing the anisotropic MRE.