Electrical Properties of Magneto-Rheological Elastomers

2008 ◽  
Author(s):  
Xiaojie Wang ◽  
Faramarz Gordaninejad ◽  
Mert Calgar ◽  
Yanming Liu ◽  
Joko Sutrisno ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Electrical Properties ◽  
Magnetic Particles ◽  
External Stimulus ◽  
Magnetorheological Elastomer ◽  
Polymer Medium ◽  
Impedance Response ◽  
Properties Of Materials ◽  
Magneto Rheological ◽  
Ferromagnetic Particles

A magnetorheological elastomer (MRE) is comprised of ferromagnetic particles aligned in a polymer medium by exposure to a magnetic field. The structures of the magnetic particles within elastomers are very sensitive to the external stimulus of either mechanical force or magnetic field, which result in multi-response behaviors in MRE. In this study, sensing properties of MREs through experimentally characterizing the electrical properties of materials and theirs interfaces with external stimulus (magnetic field or stress/strain) are investigated. A phenomenological model is proposed to model the impedance response of MREs. Results show that MRE samples exhibit significant changes in measured values of impedance and resistance in response to compressive deformation, as well as applied magnetic field.

Sensing Behavior of Magnetorheological Elastomers

2009 ◽  
Vol 131 (9) ◽  
Author(s):  
Xiaojie Wang ◽  
Faramarz Gordaninejad ◽  
Mert Calgar ◽  
Yanming Liu ◽  
Joko Sutrisno ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Electrical Properties ◽  
Magnetic Particles ◽  
External Stimulus ◽  
Magnetorheological Elastomer ◽  
Polymer Medium ◽  
Mechanical Loads ◽  
Magnetorheological Elastomers ◽  
Impedance Response ◽  
Ferromagnetic Particles

A magnetorheological elastomer (MRE) is comprised of ferromagnetic particles aligned in a polymer medium by exposure to a magnetic field. The structures of the magnetic particles within elastomers are very sensitive to the external stimulus of either mechanical force or magnetic field, which result in multiresponse behaviors in a MRE. In this study, the sensing properties of MREs are investigated through experimentally characterizing the electrical properties of MRE materials and their interfaces with external stimulus (magnetic field or stress/strain). A phenomenological model is proposed to understand the impedance response of MREs under mechanical loads and magnetic fields. Results show that MRE samples exhibit significant changes in measured values of impedance and resistance in response to compressive deformation, as well as the applied magnetic field.

Analysis of magneto rheological elastomers for energy harvesting systems

2020 ◽  
Vol 64 (1-4) ◽  
pp. 439-446
Author(s):  
Gildas Diguet ◽  
Gael Sebald ◽  
Masami Nakano ◽  
Mickaël Lallart ◽  
Jean-Yves Cavaillé
Keyword(s):  
Magnetic Field ◽  
Energy Harvesting ◽  
Shear Strain ◽  
Magnetic Induction ◽  
Magnetic Particles ◽  
Homogeneous Magnetic Field ◽  
Electrical Signal ◽  
Harvesting Systems ◽  
Dc Bias ◽  
Magneto Rheological

Magneto Rheological Elastomers (MREs) are composite materials based on an elastomer filled by magnetic particles. Anisotropic MRE can be easily manufactured by curing the material under homogeneous magnetic field which creates column of particles. The magnetic and elastic properties are actually coupled making these MREs suitable for energy conversion. From these remarkable properties, an energy harvesting device is considered through the application of a DC bias magnetic induction on two MREs as a metal piece is applying an AC shear strain on them. Such strain therefore changes the permeabilities of the elastomers, hence generating an AC magnetic induction which can be converted into AC electrical signal with the help of a coil. The device is simulated with a Finite Element Method software to examine the effect of the MRE parameters, the DC bias magnetic induction and applied shear strain (amplitude and frequency) on the resulting electrical signal.

Study of the Performance of Practical Magneto-Rheological Elastomers

2012 ◽  
Vol 430-432 ◽  
pp. 1979-1983
Author(s):  
Wei Bang Feng ◽  
Xue Yang ◽  
Zhi Qiang Lv
Keyword(s):  
Magnetic Field ◽  
Mechanical Properties ◽  
Mechanical Property ◽  
Magnetic Properties ◽  
External Magnetic Field ◽  
Magnetic Particles ◽  
Poor Performance ◽  
Electrical And Magnetic Properties ◽  
Intelligent Material ◽  
Magneto Rheological

Magneto-rheological elastomer( MR elastomer) is an emerging intelligent material made up of macromolecule polymer and magnetic particles. While a promising wide application it has in the fields of warships vibration controlling for its controllable mechanical, electrical and magnetic properties by external magnetic field, design and application of devices based on it are facing great limitations imposed by its poor performance in mechanical properties and magneto effect. Aiming at developing a practical MR elastomer, a new confecting method was proposed in this paper. Then, following this new method and using a specificly designed solidifying matrix, an amido- polyester MR elastomer was developed with its mechanical property systemically explored.

Structural Optimization Design of MR Fluid Clutch

2007 ◽  
Vol 546-549 ◽  
pp. 1673-1676 ◽  
Author(s):  
Wei Jia Meng ◽  
Zhan Wen Huang ◽  
Yan Ju Liu ◽  
Xiao Rong Wu ◽  
Yi Sun
Keyword(s):  
Magnetic Field ◽  
Mechanical Properties ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Optimization Design ◽  
Element Analysis ◽  
Mr Fluids ◽  
Magneto Rheological ◽  
Ferromagnetic Fluids ◽  
Ferromagnetic Particles

Magnetorheological (MR) fluids are suspensions of micron sized ferromagnetic particles dispersed in varying proportions of a variety of non-ferromagnetic fluids. MR fluids exhibit rapid, reversible and significant changes in their rheological (mechanical) properties while subjected to an external magnetic field. In this paper, a double-plate magneto-rheological fluid (MRF) clutch with controllable torque output have been designed. Electromagnetic finite element analysis is used to optimize the design of the clutch by using the commercial FEA software ANSYS.

scholarly journals Effect of Magnetic Field and Aggregation on Electrical Characteristics of Magnetically Responsive Suspensions for Novel Hybrid Liquid Capacitor

2019 ◽  
Vol 5 (2) ◽  
pp. 38 ◽  
Author(s):  
Kunio Shimada
Keyword(s):  
Magnetic Field ◽  
Electrical Properties ◽  
Natural Rubber ◽  
Applied Voltage ◽  
Nonlinear Response ◽  
Magnetic Particles ◽  
Particle Aggregation ◽  
Electrical Characteristics ◽  
Rubber Latex ◽  
Wide Range

Magnetically responsive fluid based on polymers of natural rubber (NR-latex) involves a magnetic compound fluid (MCF) rubber liquid. For a wide range of engineering applications of suspensions or liquids with particles, their electrical characteristics of fluidic suspensions are investigated to obtain useful results that might be important in the study of devices, such as fluidic sensors and capacitors. The author of the present paper proposes that MCF rubber liquid can be produced by combining MCF and rubber latex. The influence of the aggregation of magnetic particles and rubber molecules on electrical characteristics under a magnetic field was investigated by measuring electrical properties under an applied voltage. The electrical characteristics change with a linear or a nonlinear response, based on conditions of particle aggregation. The capacity of the electric charge also changes with the conditions of particle aggregation. These results show that MCF rubber liquid is a novel hybrid capacitor.

MONITORING INTERPARTICLE DISTANCE IN MAGNETORHEOLOGICAL COMPOSITES

2007 ◽  
Vol 21 (28n29) ◽  
pp. 4868-4874
Author(s):  
G. BOSSIS ◽  
E. COQUELLE ◽  
C. NOEL ◽  
F. GIULIERI ◽  
A. M. CHAZE
Keyword(s):  
Magnetic Field ◽  
Liquid Crystal ◽  
Energy Dissipation ◽  
Viscoelastic Properties ◽  
Magnetic Particles ◽  
Interparticle Distance ◽  
Magnetorheological Elastomer ◽  
Magnetorheological Elastomers ◽  
Magnetic Spheres ◽  
The Creation

We describe two different systems, the first one based on a magnetorheological elastomer and the second one on magnetic particles inside a liquid crystal. In both system we manage to have chain structures with particles that are not in contact. The effect of the gap between particles on the viscoelastic properties are studied. We show in particular how in magnetorheological elastomers, the energy dissipation is closely related to the creation and the motion of cavities in the gap between the particles. In liquid crystal chaining of particles can occur without applying a magnetic field. This happens if the anchoring of liquid crystal on the surface of the particles is homeotropic. We demonstrate how the combination of elastic defects and of a magnetic field allow to obtain microscopic springs made of a pair of magnetic spheres.

scholarly journals Experiments and Numerical Implementation of a Boundary Value Problem Involving a Magnetorheological Elastomer Layer Subjected to a Nonuniform Magnetic Field

2021 ◽  
Vol 88 (7) ◽  
Author(s):  
Charles Dorn ◽  
Laurence Bodelot ◽  
Kostas Danas
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Boundary Value Problem ◽  
Magnetic Particles ◽  
Boundary Value ◽  
Energetic Efficiency ◽  
Iron Core ◽  
Isotropic Layer ◽  
Magnetorheological Elastomer ◽  
Electromagnetic Coil

Abstract This study investigates experimentally and numerically the response of a magnetorheological elastomer (MRE) layer placed atop an electromagnetic coil. The MRE layer is deflected upon application of a current in the coil, which creates highly nonuniform magnetic fields. Isotropic and transversely isotropic layers (i.e., containing chains of magnetic particles) are tested experimentally, and the isotropic layer exhibits the largest deflection. To enhance the energetic efficiency of the model device, an iron core is introduced inside the electromagnetic coil, thereby leading to an increase in the resulting magnetic field near the center of the MRE layer. In parallel, the boundary value problem —including the MRE layer, the coil, the core (if present) and the surrounding air—is modeled numerically. For this, a magneto-mechanical, vector potential-based variational formulation is implemented in a standard three-dimensional finite element model at finite strains. For the material description, a recently proposed analytical homogenization-guided model is used to analyze the MRE in the “coil-only” configuration. It is then employed to predict the response of the layer in the “coil plus core” configuration, thus circumventing the need for a separate material characterization procedure. The proposed numerical simulation strategy provides a deeper understanding of the underlying complexity of the magnetic fields and of their interaction with the MRE layer. This study also reveals the importance of modeling the entire setup for predicting the response of MRE materials and, as a result, constitutes a step toward designing more efficient MRE-based devices.

Performance of silicon oil-based Magneto-Rheological fluids used for MR dampers: an experimental approach

2021 ◽  
Vol 13 ◽  
Author(s):  
Mohamed Bakr ◽  
Tamer Nabil ◽  
Ali Eldomuaty ◽  
Tamer Mansour ◽  
Hossam Hammad ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Particles ◽  
Silicone Oil ◽  
Spherical Shape ◽  
Magnetic Behavior ◽  
Power Requirement ◽  
Mr Fluid ◽  
Lithium Grease ◽  
Working Temperature ◽  
Magneto Rheological

Aim: The aim of this work was preparation of the model Magneto Rheological (MR) fluids to be used under the effect of an applied magnetic field operated under very low power requirement for the purpose of vibration reduction in automotive damper. Background: Magneto-Rheological fluids are non-Newtonian fluids, which consist of magnetic particles scattered in a base liquid – a matter that can change their characteristics when applying the magnetic field. From the previous researches, Magneto-Rheological fluids have different properties according to the preparation accuracy, ingredients, particle size and shape, type of carrier fluids and stabilizer. Also, the response of Magneto-Rheological fluids to the magnetic flux varied. Methods: : A specimen of MR fluid is prepared using four different dynamic viscosities base fluids: Silicone oil JETTA (50mpa.s, 100mpa.s, 150mpa.s and 200mpa.s) are mixed with high purity spherical shape particles of Carbonyl Iron (CI). ABRO liquid white lithium grease is added to the specimen, and its effect is determined. Results: The presence of additives has no effect on the magnetic behavior; but rather increases dynamic viscosity, especially in the presence of the external magnetic field, which is considered as a stabilizing factor. Conclusion: Adding the white lithium grease as a stabilizer delays the sedimentation of the prepared sample by 1023%. The lowest sample in sedimentation rate has the highest viscosity, which satisfies 2.7% in 24 hours, but it shows a negative effect on the magneto-rheological properties, which leads to unstable viscosity readings due to MR fluid agglutination. Working temperature is a critical parameter that can affect the behavior of MR fluid; the viscosity of MR fluid under the effect of magnetic field is inversely proportional to the working temperature. Sample DELTA is the most promising for the application in automotive dampers which are used to decrease vehicle vibration. :

Micro-Structural Model of Magneto-Rheological Composites With Magnetically Induced Stress for Harmonic Shear Deformation

2014 ◽  
Author(s):  
Yotsugi Shibuya ◽  
Hiroshi Nasuno ◽  
Katsuaki Sunakoda
Keyword(s):  
Magnetic Field ◽  
Applied Magnetic Field ◽  
Magnetic Particles ◽  
Structural Model ◽  
Large Strain ◽  
Deformation Analysis ◽  
Damping Capacity ◽  
Analysis Model ◽  
Induced Stress ◽  
Magneto Rheological

Magneto-rheological composites with magnetic particles are prepared. The magnetic particle is Fe-Si-B-Cr system and the average diameter is 10μm. Matrix of the composite is silicon gel. We characterized dynamic response of the material by shear test in magnetic field where intensities are 0 mT, 105 mT and 211 mT. The stiffness and damping capacity of the composite increase with increasing of the magnetic field. To understand mechanism of behavior of magneto-rheological composites, we make a model of the composite with periodical micro structure. The magneto-rheological composite undergoes magnetically induced internal stress field by applied magnetic field. The analysis model involved effect of the applied magnetic field as initial stress in the material. Particles and the magnetically induced stress make locally large strain field in the gel material. A large deformation analysis with the Ogden model using finite element method is made to demonstrate behavior of magneto-rheological composites. The simulation results are compared with experiment results and verified the effectiveness of the model.

Molecular Dynamics in Simulation of Magneto-Rheological Fluids Behavior

2013 ◽  
Vol 542 ◽  
pp. 11-27 ◽  
Author(s):  
Marek Barski ◽  
Małgorzata Chwał ◽  
Piotr Kędziora
Keyword(s):  
Magnetic Field ◽  
Molecular Dynamics ◽  
Molecular Dynamic ◽  
Particle Distribution ◽  
Computational Simulations ◽  
Dynamic Algorithm ◽  
Micro Scale ◽  
Macro Scale ◽  
Magneto Rheological ◽  
Ferromagnetic Particles

The present paper is devoted to computational simulations of magneto - rheological fluids behavior subjected to external magnetic fields. In order to perform these simulations the modified molecular dynamic algorithm is adopted. The theoretical model of the magneto - rheological fluid in micro scale as well as the basic interactions between the ferromagnetic particles are discussed. Moreover, the classical molecular dynamic algorithm and its necessary modifications are also described. The proposed approach makes possible to study the process of the internal structure (constructed from the ferromagnetic particles) formation under external magnetic field. The obtained results in the form of the particle distribution in the representative volume can be further used in order to evaluate the mechanical or physical properties of the fluid in macro scale, for example magnetic permeability, heat conduction, etc.

Sign in / Sign up

Export Citation Format

Share Document