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Showing papers on "Magnetorheological fluid published in 2018"


Journal ArticleDOI
TL;DR: A new class of architected materials called field responsive mechanical metamaterials (FRMMs) that exhibit dynamic control and on-the-fly tunability enabled by careful design and selection of both material composition and architecture.
Abstract: Typically, mechanical metamaterial properties are programmed and set when the architecture is designed and constructed, and do not change in response to shifting environmental conditions or application requirements. We present a new class of architected materials called field responsive mechanical metamaterials (FRMMs) that exhibit dynamic control and on-the-fly tunability enabled by careful design and selection of both material composition and architecture. To demonstrate the FRMM concept, we print complex structures composed of polymeric tubes infilled with magnetorheological fluid suspensions. Modulating remotely applied magnetic fields results in rapid, reversible, and sizable changes of the effective stiffness of our metamaterial motifs.

129 citations


Journal ArticleDOI
TL;DR: A novel variable universe fuzzy control design for vehicle semi-active suspension system with magnetorheological (MR) damper through the combination of fuzzy neural network (FNN) and particle swarm optimization (PSO) is proposed.

110 citations


Journal ArticleDOI
TL;DR: Recent progress in the search for advanced MR fluid materials with good stability is described, along with new approaches to MR flow behavior analysis, which describe the flow behavior over a wide range of shear rates.
Abstract: Magnetorheological (MR) fluids are a type of smart material with rheological properties that may be controlled through mesostructural transformations MR fluids form solid-like fibril structures along the magnetic field direction upon application of a magnetic field due to magnetopolarization of soft-magnetic particles when suspended in an inert medium A reverse structural transition occurs upon removal of the applied field The structural changes are very fast on the order of milliseconds The rheological properties of MR fluids vary with the application of a magnetic field, resulting in non-Newtonian viscoplastic flow behaviors Recent applications have increased the demand for MR materials with better performance and good long-term stability A variety of industrial MR materials have been developed and tested in numerous experimental and theoretical studies Because modeling and analysis are essential to optimize material design, a new macroscale structural model has been developed to distinguish between static yield stress and dynamic yield stress and describe the flow behavior over a wide range of shear rates Herein, this recent progress in the search for advanced MR fluid materials with good stability is described, along with new approaches to MR flow behavior analysis Several ways to improve the stability and efficiency of the MR fluids are also summarized

77 citations


Journal ArticleDOI
TL;DR: This novel sensor based on the magnetorheological elastomer and triboelectric nanogenerator that can be used for both time-varying and uniform magnetic field (UMF) sensing provides a new idea for the magnetic-field measurements in self-powered mode.
Abstract: The monitoring of the magnetic field is the most significant process for academic or industrial applications. In this study, we design a self-powered magnetic-field sensor based on the magnetorheological elastomer (MRE) and triboelectric nanogenerator (TENG) that can be used for both time-varying and uniform magnetic field (UMF) sensing. This TENG-based magnetic-field sensor (TMFS) relies on contact electrification and electrostatic induction of TENG to generate an electrical signal in response to the magnetic-induced deformation of MRE without using an external power supply. Enabled by the unique sensing mechanism and excellent magnetic-induced deformation of MRE, the TMFS exhibits a fast response (20 ms) and good magnetic-field sensing performance. The TMFS with 60 wt%-MRE shows a maximum sensitivity of 16 mV mT−1 of the magnetic field ranging from 40 to 100 mT experimentally, and the sensitivity and detection range of TMFS can be adjusted by several parameters of the device. Besides the contribution to the effective detection of UMF, this novel sensor provides a new idea for the magnetic-field measurements in self-powered mode.

69 citations


Journal ArticleDOI
TL;DR: In this paper, a new type of adaptive vibration isolator based on magnetorheological elastomer (MRE) is presented, where both a magnetic field and a preload were applied simultaneously.

65 citations


Journal ArticleDOI
01 Aug 2018-Polymer
TL;DR: In this article, the possibility of employing a suitable 3D printing technology for the development of one of the smart materials, the magnetorheological elastomer (MRE), has been explored.

64 citations


Journal ArticleDOI
TL;DR: In this paper, the coupled magneto-mechanical response of magnetorheological elastomers (MREs) has been studied and the influence of particle content and arrangement within the composite is particularly studied.
Abstract: Magnetorheological elastomers (MREs) are materials made of a soft elastomer matrix filled with magnetizable particles. These flexible composites that deform in response to an externally applied magnetic field are of special interest in advanced engineering applications such as actuators, artificial muscles or shape control. However, no systematic characterization of their coupled response has been undertaken so far, thus limiting the efficient design of MRE-based devices. In this study, we propose a framework—relying on both specially designed samples and a dedicated experimental setup—to characterize experimentally the coupled magneto-mechanical response of MREs since magnetization within the sample is nearly uniform and structural-dependent effects are minimized. The influence of particle content and arrangement within the composite are particularly studied and the corresponding experimental results give some insight into the underlying microstructural mechanisms that are responsible for the macroscopic deformation of MREs under combined magnetic and mechanical loading conditions. Such data is crucial for the design of new MRE composite materials in which the microstructure is optimized (to have the largest coupling effect with minimal energy input).

62 citations


Journal ArticleDOI
01 Mar 2018
TL;DR: In this article, the authors evaluate the effect of vibrations on ride quality and comfort of a passenger vehicle, using the Sperl test set on a railway vehicle, and find that vibrations are generated due to the interaction between wheel and track.
Abstract: In a railway vehicle, vibrations are generated due to the interaction between wheel and track. To evaluate the effect of vibrations on the ride quality and comfort of a passenger vehicle, the Sperl...

62 citations


Journal ArticleDOI
TL;DR: In this article, the authors deal with the manufacturing and testing of sandwich beams with carbon/epoxy composite skins and a honeycomb core filled with magnetorheological elastomer (MRE) in different proportions of magneto/elastomer.

61 citations


Journal ArticleDOI
TL;DR: In this article, a magnetorheological fluid (MRF) system containing porous mono-disperse magnetite (Fe3O4) spheres synthesized by solvothermal method is demonstrated.

59 citations


Journal ArticleDOI
TL;DR: In this article, different magnetorheological fluids are synthesized by changing fluid composition to finish bio-titanium alloy using novel magnetic field assisted finishing tool, which is used to generate different surface morphologies on the bio titanium Alloy.
Abstract: Surface morphology i.e. surface roughness, surface texture, and surface wettability is a necessary requirement to lengthen implant’s life and also to increase its performance. The requirement of surface morphology of each implant varies depending upon its applications. In the present study, a nanofinishing process, Magnetic Field Assisted Finishing is used to generate different surface morphologies on the bio-titanium alloy. For this purpose, different magnetorheological fluids are synthesized by changing fluid composition to finish bio-titanium alloy using novel magnetic field assisted finishing tool. Further, the surface characteristics of the polished surfaces with different magnetorheological fluids are characterized for surface roughness, surface texture and to confirm their surface wettability (i.e. whether the surface is hydrophilic or hydrophobic). Ultrafine surface roughness (Ra = 10 nm) is achieved using magnetorheological fluid of Type - I having very smooth surface topography. While little bit rough surface (Ra = 70 nm) and less smooth surface topography is obtained using Type - II magnetorheological fluid. Experimentally it is observed that bio-titanium polished surface using magnetorheological fluid with Type - I polishing medium is hydrophilic in nature and it is better suited for semi-permanent type of implants and also for implants which engaged with relative motion in human body. While, magnetorheological fluid of type II should be selected to polish permanent implants which requires hydrophobic surface.

Journal ArticleDOI
TL;DR: In this article, the dynamic buckling analysis of sandwich plates with magnetorheological (MR) fluid core and piezoelectric nanocomposite facesheets is presented.

Journal ArticleDOI
TL;DR: A model mechanism is established to analyze the potential benefits of using flower-like particles as the active phase compared with the benefits of use conventional spherical particles, and the tunable range of the field-induced storage modulus of MREs is improved upon using the flower- like particles.
Abstract: The field-induced storage modulus is an important parameter for the applications of magnetorheological (MR) elastomers. In this study, a model mechanism is established to analyze the potential benefits of using flower-like particles as the active phase compared with the benefits of using conventional spherical particles. To verify the model mechanism and to investigate the difference in dynamic viscoelasticity between MREs with spherical particles and flower-like particles, flower-like cobalt particles and spherical cobalt particles with similar particle sizes and magnetic properties are synthesized and used as the active phase to prepare MR elastomers. As the model predicts, MREs with flower-like cobalt particles present a higher crosslink density and enhanced interfacial bond strength, which leads to a higher storage modulus and higher loss modulus with respect to MREs with spherical cobalt particles. The tunable range of the field-induced storage modulus of MREs is also improved upon using the flower-like particles as the active phase.

Journal ArticleDOI
TL;DR: In this paper, a magnetorheological shear-stiffening elastomer (MSTE) was prepared by dispersing carbonyl iron particles (CIPs), which was synthesized by co-polymerization of Shear-Stiffening Gel (STG) and methyl vinyl silicone rubber (VMQ).

Journal ArticleDOI
TL;DR: In this article, a novel approach using two opposite magnetic poles has been used to enhance the magnetic flux density distribution between the tool tip and the copper workpiece surface, and a nano-finished surface with very few shallow scratches was achieved.
Abstract: Ball-end magnetorheological (MR) finishing process utilizes the magnetically controlled stiffened ball of an MR fluid for finishing purposes. Copper is a mechanically soft and chemically reactive material, so it is difficult to finish up to the nanometer-order level by traditional and most of the advanced finishing processes. In this research work, the problems associated with ball-end MR finishing of copper have been explored and a fluid composition suitable for the finishing of copper has been developed. A novel approach using two opposite magnetic poles has been used to enhance the magnetic flux density distribution between the tool tip and the copper workpiece surface. The same has been magnetically simulated and verified experimentally. The effect of fluid composition parameters has been analyzed by the statistical model developed by response surface. After 30 minutes of finishing time, a nano-finished surface with very few shallow scratches was achieved.

Journal ArticleDOI
TL;DR: In this paper, a short review of the main mathematical models of magnetorheological dampers is proposed and the main issues that occur in MRDs experimental characterization is reported and discussed.
Abstract: Magnetorheological (MR) fluids are capable of manifesting a rheological behaviour change by means of a magnetic field application and can be employed in many complex systems in many technical fields. One successful example is their use in the development of dampers: magnetorheological dampers (MRDs) are widespread in vibration control systems, as well as civil engineering applications (i.e., earthquake or seismic protection), impact absorption and vibration isolation technology in industrial engineering, and advanced prosthetics in biomedical fields. In the past, many studies have been conducted on MRDs modeling and characterization, but they have usually been focused more on the theoretical models than on the experimental issues. In this work, an overview of both of them is proposed. In particular, after an introduction to the physics of the magnetorheological effect, a short review of the main mathematical models of MRDs is proposed. Finally, in the second part of this study an overview of the main issues that occur in MRDs experimental characterization is reported and discussed.

Journal ArticleDOI
TL;DR: In this article, the cylindrical permanent magnet tool with magnetorheological polishing fluid at its tip surface is rotated over the copper alloy workpiece surface and performs finishing by the stiffened magnetoric polishing fluids, and the results obtained from finite element analysis and experimentation assure that the new design of permanent magnetors is capable to nano-finish of diamagnetic materials such as copper alloy etc.
Abstract: Nano-finishing of a material surface is one of the most required properties in industry. There is high need of nano-finishing of diamagnetic materials such as copper and its alloys in electronic industries and electrode of electric discharge machining. Some industries like laser, aerospace, dentistry and metal optics etc. widely use highly finished copper mirrors. As copper is soft and chemically reactive material, its surface finishing at nano level is a difficult tasked. To fulfill this need, a new magnetorheological technique for precise surface finishing of diamagnetic materials has been conceptualized. Two cylindrical permanent magnets along with magnetorheological polishing fluid have been used to finish the diamagnetic copper alloy workpiece. The cylindrical permanent magnets tool with magnetorheological polishing fluid at its tip surface is rotated over the copper alloy workpiece surface and performs finishing by the stiffened magnetorheological polishing fluid. The permanent magnets finishing tool along with magnetorheological polishing fluid at its tip surface and diamagnetic copper workpiece have been modeled as well as simulated in Maxwell Ansoft V13 (student version) software. Distribution of magnetic flux density in the working gap is obtained and analyzed. Experiments are performed on the copper alloy workpiece and least Ra value of 28.8 nm is achieved in finishing time of 7.5 min from its initial value of 273.6 nm. Surface characteristics of both polished and unpolished workpiece are analyzed with the scanning electron microscopy (SEM) and atomic force microscopy (AFM). The results obtained from finite element analysis and experimentation assures that the new design of magnetorheological finishing tool using permanent magnets is capable to nano-finish of diamagnetic materials such as copper alloy etc.

Journal ArticleDOI
TL;DR: In this article, carbon allotropes ( fullerene powder, carbon nanotubes, graphene nanoplatelets) were added into the carbonyl iron-based magnetorheological fluids to examine their effect on stability and utility properties.

Journal ArticleDOI
05 Dec 2018-Polymers
TL;DR: This article focuses on studying the rheological behavior of isotropic and anisotropic magnetorheological elastomers (MREs), made of carbonyl iron microparticles dispersed into a silicone–rubber matrix by considering 20 and 30 wt % ofmicroparticles.
Abstract: This article focuses on studying the rheological behavior of isotropic and anisotropic magnetorheological elastomers (MREs), made of carbonyl iron microparticles dispersed into a silicone⁻rubber matrix by considering 20 and 30 wt % of microparticles. Sample sets were prepared for each composition, with and without the application of an external magnetic field. Experimental measurements of the material rheology behavior were carried out by a shear oscillatory rheometer at constant temperature, to determine both the shear storage modulus (G') and shear loss modulus (G'') for all characterized samples. Then, experimental data collected from the isotropic and the anisotropic material samples were used to plot the Cole-Cole diagrams to quantify the interfacial adhesion between carbonyl iron microparticles and the silicone-rubber matrix. Furthermore, the Fractional Zener Model (FZM) with two spring-pots in series is used for quantitative analysis of collected experimental data.

Journal ArticleDOI
TL;DR: In this paper, the authors presented constitutive models of magnetorheological (MR) fluids, which can predict the shear and dynamic yield stress depending on temperature, using the extreme learning machine (ELM) method.
Abstract: This work presents constitutive models of magnetorheological (MR) fluids, which can predict the shear and dynamic yield stress depending on temperature. Two existing models, the Herschel–Bulkley rheological and power law model, which are frequently used in MR fluid research, are adopted and modified to take the temperature into account. A new constitutive model of MR fluids is developed using the extreme learning machine (ELM) method. In this development, among many machine learning approaches, a simple and efficient learning algorithm for a single hidden layer feed-forward neural network (SLFN) is adopted and applied to the rheological model of MR fluids. The temperature, shear rate, and magnetic field are treated as inputs, and the shear stress is taken as an output. After formulating the models associated with experimental coefficients, the two most important properties of MR fluids; the shear and yield stress are predicted and compared with the measured values. The prediction accuracy for the field-dependent rheological properties of MR fluids in several different temperatures is evaluated and compared. It is shown that the ELM model developed in this work provides the best accuracy, followed by two other modified constitutive equations.


Journal ArticleDOI
TL;DR: In this article, the dynamic mechanical analysis (DMA) tests have been performed to determine the viscoelastic properties of magnetorheological elastomers with different test conditions.

Journal ArticleDOI
TL;DR: In this article, the steady-state shear response of polydisperse Ni-Zn ferrite-submicrospheres-based magnetorheological fluids (MRFs) was reported.

Journal ArticleDOI
TL;DR: In this paper, the authors used magnetic fluids as active elements in sealing for improving sealing capacity and minimizing friction torque, with application to the spindles of high precision machine tools.
Abstract: The research work reported in this paper is focused on the use of magnetic fluids as active elements in seals for improving sealing capacity and minimizing friction torque, with application to the spindles of high precision machine tools. The prototype design was optimized following numerical computation of the magnetic field in the rings of the seal. Two magnetic fluids were analyzed for their use in the seals: a ferrofluid and magnetorheological fluid. The sealing capacity of the MRF based seals was higher than 45 kPa per ring, but the friction of the seal in the bearing was 8 N·m, too large for the use in precision spindles of machine tools because of the energy consumption and heat generation. The ferrofluid seal achieved sealing capacity around 9 kPa per ring, good enough to be used in the spindles of machine tools, with a friction 0.25 N·m and low energy consumption. The feasibility of using ferrofluids for developing high performance seals for high precision spindles and the validity of the simulation models has been demonstrated experimentally.

Journal ArticleDOI
TL;DR: In this article, a novel magnet-induced aligning magnetorheological elastomer (MIMRE) based on ultra-soft polymeric matrix was prepared through an innovative synthetic approach, enabling the magnetic particles to mobile and align in elastic matrix under magnetic field at room temperature.

Journal ArticleDOI
TL;DR: In this article, an influence of carbonyl iron (CI) particles' corrosion on magnetorheological performance of their silicone-oil suspensions was investigated, which showed lower values of the yield stress, which was significantly manifested at higher magnetic field intensities due to lower saturation magnetization of the particles.

Journal ArticleDOI
TL;DR: In this paper, a semi-active tuned mass damper which incorporated four multi-layered structures fabricated using magnetorheological elastomers was investigated and evaluated to protect a building from earthquake, extensive simulation and experimental testing were conducted.
Abstract: This study investigated and evaluated a semi-active tuned mass damper which incorporated four multi-layered structures fabricated using magnetorheological elastomers. The four magnetorheological elastomer structures formed a square and provided the tuned mass damper variable stiffness used to track the excitation frequencies. This design not only increases the stability of the tuned mass damper but more importantly eliminates the magnetic circuit gap in a design which we used in the past because all four of the magnetic circuits used to control the magnetorheological elastomer isolators are closed circuits. In order to verify the capability of the magnetorheological elastomer–based tuned mass damper to protect a building from earthquake, extensive simulation and experimental testing were conducted. The swept sinusoidal signal and the scaled 1940 El Centro earthquake record were used to excite a scaled three-story building. Both simulation and experiment have verified that the magnetorheological elastomer–...

Journal ArticleDOI
TL;DR: It was demonstrated that the damping force increased as the number of operating cycles increases, both when the damper is turn on (on-state) and off (off-state).It was observed that the particle size and shape changed due to the long operation, showing irregular particles.
Abstract: This paper investigates the field-dependent rheological properties of magnetorheological (MR) fluid used to fill in MR dampers after long-term cyclic operation. For testing purposes, a meandering MR valve was customized to create a double-ended MR damper in which MR fluid flowed inside the valve due to the magnetic flux density. The test was conducted for 170,000 cycles using a fatigue dynamic testing machine which has 20 mm of stroke length and 0.4 Hz of frequency. Firstly, the damping force was investigated as the number of operating cycles increased. Secondly, the change in viscosity of the MR fluid was identified as in-use thickening (IUT). Finally, the morphological observation of MR particles was undertaken before and after the long-term operation. From these tests, it was demonstrated that the damping force increased as the number of operating cycles increases, both when the damper is turn on (on-state) and off (off-state). It is also observed that the particle size and shape changed due to the long operation, showing irregular particles.

Journal ArticleDOI
TL;DR: Recent research not only on a wide variety of MR elastomers focusing on various magnetic particles, elastomeric matrices, additives and particle modification methods, but also on their characteristics including MR properties from dynamic oscillation tests is covered along with their mechanical properties such as the Payne effect, tensile strength and engineering applications.
Abstract: The magnetorheological (MR) elastomer as a hard and soft hybrid functional material, a composite material consisting of magnetic hard particles embedded in elastomeric soft matrix, is a branch of MR materials that are functional smart materials rapidly responding to external magnetic fields. These tunable properties of MR elastomers facilitate a variety of applications. In this brief review paper, in addition to general information on the MR elastomers, recent research not only on a wide variety of MR elastomeric systems focusing on various magnetic particles, elastomeric matrices, additives and particle modification methods, but also on their characteristics including MR properties from dynamic oscillation tests is covered along with their mechanical properties such as the Payne effect, tensile strength and engineering applications.

Journal ArticleDOI
TL;DR: The magnetic field and particle-concentration dependent steady-state shear-responses of rod shaped Li-Zn ferrite particle based magnetorheological fluids (MRFs) are reported and, based on the on-state to off-state viscosity ratio (ηon/ηoff), the optimum particle concentration required for energy- and cost-efficient operation of the MRFs can be chosen.
Abstract: We report the magnetic field and particle-concentration dependent steady-state shear-responses of rod shaped Li–Zn ferrite particle based magnetorheological fluids (MRFs). Rod-shaped soft ferrimagnetic Li–Zn ferrite (Li0.4Zn0.2Fe2.4O4) particles were synthesized using the combustion synthesis method. MRFs of three different particle-concentrations (ϕ = 0.1, 0.2 and 0.4, in weight fraction) were prepared using silicone oil. Their yield strength and dynamic viscosity were studied at different applied magnetic fields (B). With an increase in B and ϕ, the yield strength (τY) of the MRFs increases. This behaviour is assigned to the formation of stronger columnar structures of the magnetically interacting particles which resist the flow (shear) of the MRF. For the MRF with ϕ = 0.4 and B = 1.2 T, we observed a maximum τY value of ∼1.25 kPa. Furthermore, we observed that, based on the on-state to off-state viscosity ratio (ηon/ηoff) at a particular operating B value, the optimum particle concentration required for energy- and cost-efficient operation of the MRFs can be chosen. The absence of a stabilizing-agent or de-agglomerating-coating, the low density, and the excellent oxidation- and corrosion-resistance of the soft ferrimagnetic rod-shaped Li–Zn ferrite particles make this MRF-system highly versatile and economical for many magneto-mechanical applications.