scholarly journals Magneto-Rheological Elastomer Composites. A Review

2020 ◽  
Vol 10 (14) ◽  
pp. 4899 ◽  
Author(s):  
Sneha Samal ◽  
Marcela Škodová ◽  
Lorenzo Abate ◽  
Ignazio Blanco
Keyword(s):  
Magnetic Field ◽  
Smart Materials ◽  
Mechanical Response ◽  
Viscoelastic Behavior ◽  
Shear Mode ◽  
Dynamic Shear ◽  
Elastomeric Matrix ◽  
Elastomer Composites ◽  
Magneto Rheological ◽  
Micro Structures

Magneto-rheological elastomer (MRE) composites belong to the category of smart materials whose mechanical properties can be governed by an external magnetic field. This behavior makes MRE composites largely used in the areas of vibration dampers and absorbers in mechanical systems. MRE composites are conventionally constituted by an elastomeric matrix with embedded filler particles. The aim of this review is to present the most outstanding advances on the rheological performances of MRE composites. Their distribution, arrangement, wettability within an elastomer matrix, and their contribution towards the performance of mechanical response when subjected to a magnetic field are evaluated. Particular attention is devoted to the understanding of their internal micro-structures, filler–filler adhesion, filler–matrix adhesion, and viscoelastic behavior of the MRE composite under static (valve), compressive (squeeze), and dynamic (shear) mode.

scholarly journals Investigation on the Mechanical Properties of MRE Compounds

Machines ◽  
2019 ◽  
Vol 7 (2) ◽  
pp. 36 ◽  
Author(s):  
Renato Brancati ◽  
Giandomenico Di Massa ◽  
Stefano Pagano
Keyword(s):  
Magnetic Field ◽  
Mechanical Properties ◽  
Smart Materials ◽  
Testing Machine ◽  
Static Test ◽  
Vibration Isolators ◽  
Elastomeric Matrix ◽  
Magneto Rheological ◽  
Stiffness And Damping ◽  
Rheological Effect

This paper describes an experimental investigation conducted on magneto-rheological elastomers (MREs) with the aim of adopting these materials to make mounts to be used as vibration isolators. These materials, consisting of an elastomeric matrix containing ferromagnetic particles, are considered to be smart materials, as it is possible to control their mechanical properties by means of an applied magnetic field. In the first part of the paper, the criteria adopted to define the characteristics of the material and the experimental procedures for making samples are described. The samples are subjected to a compressive static test and are then, adopting a testing machine specially configured, tested for shear periodic loads, each characterized by a different constant compressive preload. The testing machine is equipped with a coil, with which it is possible to vary the intensity of the magnetic field crossing the sample during testing to evaluate the magneto-rheological effect on the materials’ characteristics in terms of stiffness and damping.

3D Printed Magnetorheological Elastomers

2017 ◽  
Author(s):  
Anil K. Bastola ◽  
Milan Paudel ◽  
Lin Li
Keyword(s):  
Magnetic Field ◽  
Magnetic Particles ◽  
Damping Ratio ◽  
Shear Mode ◽  
Layer By Layer ◽  
Vibration Absorption ◽  
Spring Element ◽  
Elastomeric Matrix ◽  
3D Printed ◽  
Mr Effect

In this study, 3D printed magnetorheological (MR) elastomer has been characterized through a force vibration testing. The 3D printed MR elastomer is a composite consisting three different materials, magnetic particles and two different elastomers. The MR elastomers were printed layer-by-layer by encapsulating MR fluid within the polymeric elastomer and then allowed to cure at room temperature. The 3D printing allowed to print various patterns of magnetic particles within the elastomeric matrix. In the presence of an external magnetic field, both elastic and damping properties of the 3D printed MR elastomers were changed. Natural frequency, stiffness, damping ratio, damping coefficient, and shear modulus were increased with increasing magnetic field. For the single degree-of-freedoms system, shear mode MR elastomers suppressed the transmitted vibration amplitude up to 31.4% when the magnetic field was 550 mT. The results showed that the 3D printed MR elastomer could be used as a tunable spring element for vibration absorption or isolation applications. However, further optimization of the magnetic particles’ configurations should be performed to obtain the higher MR effect.

Analysis of Magneto Rheological Fluid Journal Bearing

2019 ◽  
Vol 895 ◽  
pp. 152-157 ◽  
Author(s):  
B. Narasimha Rao ◽  
A. Seshadri Sekhar
Keyword(s):  
Magnetic Field ◽  
Newtonian Fluid ◽  
Carrying Capacity ◽  
Smart Materials ◽  
Journal Bearing ◽  
Fluid Film ◽  
Load Carrying Capacity ◽  
Mr Fluid ◽  
Load Carrying ◽  
Magneto Rheological

Magneto Rheological (MR) fluids are a class of smart materials where the shear stress is not directly proportional to rate of shear. The viscosity of fluid changes as magnetic field changes and hence this phenomenon is very useful in bearing-rotor system for attenuating the vibrations. In the present study the application of MR fluid as lubricant instead of Newtonian fluid in the journal bearing is explored through steady state, dynamic characteristics and stability. MR fluid film has been modeled as per Bingham rheological model. FEM with three node triangular elements has been used to solve the Reynolds equation both for the Newtonian fluid film and MR fluid film. The results show the load carrying capacity in the case of MR fluid journal bearing is higher than that of using the Newtonian fluid. The load carrying capacity increases with the increasing magnetic field for all eccentricity ratios. The results also show better stability of the bearing using MR fluid at higher eccentricity ratios. The unbalance response of the rotor mounted on the journal bearing using MR fluid is also estimated to be lower than that of with the Newtonian fluid.

A state of art on magneto-rheological materials and their potential applications

2018 ◽  
Vol 29 (10) ◽  
pp. 2051-2095 ◽  
Author(s):  
Raju Ahamed ◽  
Seung-Bok Choi ◽  
Md Meftahul Ferdaus
Keyword(s):  
Magnetic Field ◽  
Smart Materials ◽  
Wide Spectrum ◽  
Materials Modeling ◽  
Different Types ◽  
Potential Applications ◽  
Magneto Rheological ◽  
Designed Materials ◽  
External Stimuli ◽  
The Magnetic Field

Smart materials are kinds of designed materials whose properties are controllable with the application of external stimuli such as the magnetic field, electric field, stress, and heat. Smart materials whose rheological properties are controlled by externally applied magnetic field are known as magneto-rheological materials. Magneto-rheological materials actively used for engineering applications include fluids, foams, grease, elastomers, and plastomers. In the last two decades, magneto-rheological materials have gained great attention of researchers significantly because of their salient controllable properties and potential applications to various fields such as automotive industry, civil environment, and military sector. This article offers a recent progressive review on the magneto-rheological materials technology, especially focusing on numerous application devices and systems utilizing magneto-rheological materials. Conceivable limitations, challenges, and comparable advantages of applying these magneto-rheological materials in various sectors are analyzed critically, which provides a clear pathway to the researchers in selecting and utilizing these materials. The review starts with an introduction to the elementary description of magneto-rheological materials and their significant contribution in various fields. Following this, different types of the magneto-rheological materials, modeling of the magneto-rheological materials, magneto-rheological material–based devices, and their applications have been extensively reviewed to promote practical use of magneto-rheological materials in a wide spectrum of the application from the automobile to medical device.

scholarly journals Development and testing of controlled adaptive fiber-reinforced elastomer composites

2016 ◽  
Vol 88 (3) ◽  
pp. 345-353 ◽  
Author(s):  
Chokri Cherif ◽  
Rico Hickmann ◽  
Andreas Nocke ◽  
Matthias Schäfer ◽  
Klaus Röbenack ◽  
...  
Keyword(s):  
Smart Materials ◽  
Longitudinal Direction ◽  
Loop Control ◽  
Elastomeric Matrix ◽  
Control Automation ◽  
Glass Fiber Reinforcement ◽  
Flow Through ◽  
Elastomer Composites ◽  
Set Up ◽  
High Deformability

The integration of shape memory alloys (SMAs) into textile-reinforced composites produces a class of smart materials whose shape can be actively influenced. In this paper, Ni-Ti SMA wires are inserted during the weaving of a glass fiber reinforcement textile. This “active” reinforcement is then combined with an elastomeric matrix to produce a highly flexible composite sheet, which maintains high rigidity in the longitudinal direction. By activating the SMAs, high deflection ratios of up to 35% (relative to the component's length) are achieved. To adjust the composite's deflection to defined values, a closed-loop control is set up to adjust the current flow through the SMA wires. A control algorithm is designed and evaluated for several test cases. The high deformability and the controllable behavior show the high potential of these materials for applications such as aerodynamic flow control, automation and architecture.

Investigation on the Dynamic Shearing Characteristics of Magnetic Responsive Gel

2011 ◽  
Author(s):  
Katsuaki Sunakoda ◽  
Naoki Yamamoto ◽  
Hiroshi Nasuno ◽  
Hirohisa Sakurai
Keyword(s):  
Magnetic Field ◽  
Physical Properties ◽  
Storage Modulus ◽  
Smart Materials ◽  
Loss Modulus ◽  
Active Vibration Control ◽  
Hysteresis Loops ◽  
Active Vibration ◽  
Magneto Rheological ◽  
Dynamic Shearing

Material which would be largely changed its physical properties such as storage modulus and loss modulus under magnetic field has a potential of application on industrial fields. Magneto-rheological (MR) fluid has been widely studied since its viscosity is changed under magnetic field, but it is restricted for application of the industrial fields as it has liquid nature. Authors are proceeding with the development of magnetic responsive gels which contain the magnetic responsive particles in consideration of their prior studies. Three kinds of magnetic gels are selected and dynamic shearing characteristics are examined. Storage modulus and loss modulus are obtained under different dynamic frequencies and different magnetic fluxes. Some physical properties such as storage modulus and loss modulus are largely changed by applying magnetic field. The developed gels have an effect of energy dissipation, judging from hysteresis loops of stress-strain. And these smart materials have a potential of semi active vibration control materials.

scholarly journals Magneto-mechanical characterization of magnetorheological elastomers

2019 ◽  
Vol 30 (17) ◽  
pp. 2534-2543 ◽  
Author(s):  
Alberto Bellelli ◽  
Andrea Spaggiari
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Analysis Of Variance ◽  
Compression Test ◽  
Mechanical Behaviour ◽  
Smart Materials ◽  
Mechanical Response ◽  
Ferromagnetic Material ◽  
Bending Test ◽  
Magnetorheological Elastomers

This work analyses the properties and the magneto-mechanical characteristics of magnetorheological elastomers, a class of smart materials not yet broadly investigated. First, set of several samples of this material was manufactured, each one characterized by a different percentage of ferromagnetic material inside the viscoelastic matrix. The specimens were manufactured in order to create isotropic and anisotropic configurations, respectively, with randomly dispersed ferromagnetic particles or with an aligned distribution, obtained through and external magnetic field. Then, the mechanical behaviour of each sample was analysed by conducting a compression test, both with and without an external magnetic field. Moreover, a three-point bending test was also performed on the same specimens. Stiffness, deformation at maximum stress and specific energy dissipated were calculated based on the experimental data. The results were analysed considering the mechanical responses, and an analysis of variance was carried out in order to assess the statistical influence of each variable. The experimental results highlighted a strong correlation between the percentage of ferromagnetic material in each sample and its mechanical behaviour. The anisotropicity of the material, aligned in columnar structures, also affects the stiffness measured in the compression test, while the external magnetic field’s main contribution is to reduce the samples’ maximum deformation. Using analysis of variance results as guidelines, we built a simple phenomenological model which produces quite reliable predictions regarding the mechanical response of the magnetorheological elastomers under compressive stress.

Smart Materials Based on Magnetorheological Composites

2012 ◽  
Vol 714 ◽  
pp. 167-173 ◽  
Author(s):  
Marcin Masłowski ◽  
Marian Zaborski
Keyword(s):  
Magnetic Field ◽  
Smart Materials ◽  
Magnetic Field Effect ◽  
Cross Linking ◽  
Vibrating Sample Magnetometer ◽  
Magnetorheological Elastomer ◽  
Gamma Iron ◽  
Magnetorheological Elastomers ◽  
Elastomer Composites ◽  
Ferromagnetic Particles

Magnetorheological elastomer composites (MREs) based on different magnetoactive fillers such as: carbonyl iron powder (CIP), gamma iron oxide (γ-Fe2O3), micro-and nanosize Fe3O4 are reported and studied. MREs were obtained from various elastomer matrixes such as: ethylene propylene, acrylonitrile butadiene, silicone, ethylene-octene and polyoctenamer rubbers. To align particles in elastomer, cross-linking process took place in magnetic field. Effect of the amount of ferromagnetic particles and their arrangement on the microstructure and properties in relation to the external magnetic field was examined. The microstructure, magnetic and magnetoreological properties of compositions were investigated with scanning electron microscopy (SEM), vibrating sample magnetometer (VSM) and ARES Rheometer with magnetic device. Cross-linking density and mechanical properties of the composites were also studied. It was found that microstructure anisotropy has significant effect on the properties of magnetorheological elastomers. Moreover, different amount of magnetoactive fillers influence mechanical and magnetic properties of the vulcanizates. Many essential conclusions occur after application the wide variety of elastomer matrixes filled with different ferromagnetic particles in the context of preparation process of smart materials based on magnetorheological elastomer composites.

Dynamic Testing and Modeling of Magneto-Rheological Elastomers

2009 ◽  
Author(s):  
Muhammad Usman ◽  
Dong-Doo Jang ◽  
In-Ho Kim ◽  
Hyung-Jo Jung ◽  
Jeong-Hoi Koo
Keyword(s):  
Magnetic Field ◽  
Dynamic Behavior ◽  
Dynamic Testing ◽  
Experimental Tests ◽  
Shear Loading ◽  
Shear Mode ◽  
Loading Frequency ◽  
Engineering Structures ◽  
Exciting Frequency ◽  
Magneto Rheological

This study presents the dynamic numerical model of magneto-rheological elastomers (MREs) along with the dynamic testing of the material under various loading conditions. Primarily the loading in shear mode is considered in this study because many civil engineering structures are subjected to shear loading. Experimental tests were carried out in order to characterize the dynamic behavior of MREs. A test setup was designed and fabricated to load the MRE samples in shear mode with varying magnetic fields. A series of shear tests of MRE samples were performed under various magnetic field values, amplitudes and frequencies of loading. The test results show that the material stiffness is increased with increasing magnetic field and loading frequency within the ranges of the magnetic field and exciting frequency considered in this work. Based on the experimental results, a dynamic model was developed to capture the dynamic behavior of the MRE.

Actuation Behavior in Patterned Magnetorheological Elastomers: Simulation, Experiment, and Modeling

2012 ◽  
Author(s):  
Paris von Lockette
Keyword(s):  
Magnetic Field ◽  
Smart Materials ◽  
Magnetic Particles ◽  
Constitutive Models ◽  
Barium Hexaferrite ◽  
Shear Stiffness ◽  
Silicone Elastomer ◽  
Dynamic Shear ◽  
Magnetorheological Elastomers ◽  
Magnetic Symmetry

Magnetorheological elastomers (MREs) are an emerging class of smart materials whose mechanical behavior varies in the presence of a magnetic field. Historically MREs have been comprised of soft-magnetic iron particles in a compliant matrix such as silicone elastomer. Numerous works have experimentally cataloged the MRE effect, or increase in shear stiffness, versus the applied field. Several other researchers have derived constitutive models for the large deformation behavior of MREs. In almost all cases the arrays of embedded particles, and or the particles themselves, are assumed magnetically symmetric with respect to the external magnetic field, i.e. the bulk materials exhibit magnetic symmetry in the given experimental or analytical configuration. In this work the author presents results of dynamic shear experiments, Lagrangian dynamic analysis, and static shear simulations on MRE material systems that exhibit broken magnetic symmetry. These new materials utilize barium hexaferrite powder as the magnetically anisotropic filler combined with a compliant silicone elastomer matrix. Simulations of representative laminate structures comprised of varied arrays of magnetic particles exhibit novel actuation behaviors including reversible shearing deformation, variable magnetostriction, and most surprisingly, piezomagnetism. Results of dynamic shear experiments and analytical modeling support predicted shearing actuation responses in MREs having broken symmetry and only in those systems.

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