Study on the trajectory of magnetic particles in the process of magnetorheological elastomer pre-structure

2022 ◽  
pp. 169014
Author(s):  
Zhiqiang Xu ◽  
Zhifa Tang ◽  
Heng Wu ◽  
Xinqian Bo ◽  
Feng Chen ◽  
...  
Keyword(s):  
Magnetic Particles ◽  
Magnetorheological Elastomer

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.

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.

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.

The Study of Magnetorheological Elastomer Based on Natural Rubber (NR)/Polybutadiene Rubber (BR) Hybrid Matrix: Experimental and Numerical Simulation

2019 ◽  
Author(s):  
Xincheng Song ◽  
Wenju Wang ◽  
Fufeng Yang ◽  
Guoping Wang ◽  
Xiaoting Rui
Keyword(s):  
Numerical Simulation ◽  
Natural Rubber ◽  
Smart Materials ◽  
Magnetic Particles ◽  
Mixing Time ◽  
Homogeneous System ◽  
Thermomechanical Analysis ◽  
Magnetorheological Elastomer ◽  
Hybrid Matrix ◽  
Polybutadiene Rubber

Abstract Magnetorheological elastomer (MRE) is a new kind of smart materials whose mechanical properties can be controlled under external magnetic field and it is mainly consist of matrix materials and magnetic particles. In this work, the natural rubber (NR)/polybutadiene rubber (BR) hybrid matrix based MRE were prepared and the compatibility of NR and BR were studied. The hybrid matrix was prepared by physical mixing method. The characterization results showed that the BR had excellent compatibility with NR. The measurement result using rheological showed that the MR effect can be increased to 44.19% by adding of BR. The dynamic thermomechanical analysis showed that the hybrid matrix formed a homogeneous system when the ratio of BR and NR is 1/9 and 3/7. The particles was mixed with matrix using physical technology. The process of mixing was analyzed by numerical simulation. The simulation result showed that the increase of diameter of particles would increase the temperature and velocity of matrix in mixing. The particles was distributed evenly at enough mixing time and the mixing time was decreased with the diameter of particles.

Study of crosslink structure and dynamic mechanical properties of magnetorheological elastomer: Effect of vulcanization system

2019 ◽  
Vol 30 (8) ◽  
pp. 1189-1199 ◽  
Author(s):  
Guanxin Shi ◽  
Wenju Wang ◽  
Huanglei Lu ◽  
Guoping Wang ◽  
Fufeng Yang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Smart Materials ◽  
Crosslink Density ◽  
Magnetic Particles ◽  
Dynamic Mechanical Properties ◽  
Zero Field ◽  
Magnetorheological Elastomer ◽  
Dynamic Mechanical ◽  
Particle Chains

Magnetorheological elastomers are a kind of intelligent and smart materials which are mainly composed of rubbery polymers and soft magnetic particles. The role of various vulcanization systems on the crosslink structures, curing properties, and dynamic mechanical properties of natural rubber–based magnetorheological elastomer was investigated. Conventional, semi-efficient, and efficient vulcanization systems were used and compared. It was found that the content of polysulfide linkages decreased and the monosulfide linkages increased when the vulcanization system was changed from conventional to semi-efficient and efficient vulcanization systems, respectively. The crosslink density has the same tendency with the content of polysulfide linkages. In all vulcanization systems, the zero-field modulus, magnetic-induced modulus, controllability of damping, and the degree of the influence of Payne effect of the samples had an increasing trend when the crosslink density decreased. Evidence from micrographs of scanning electron microscope showed that this was because the particle chains in the low crosslink density composites were longer and more aligned. As the proportion of monosulfide linkages increased, the value of the loss factor increased and the modulus of the composites was more affected by the increasing frequency.

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.

Characterization of actuation properties of magnetorheological elastomers with embedded hard magnetic particles

2012 ◽  
Vol 23 (9) ◽  
pp. 1049-1054 ◽  
Author(s):  
Jeong-Hoi Koo ◽  
Alexander Dawson ◽  
Hyung-Jo Jung
Keyword(s):  
Magnetic Materials ◽  
Magnetic Particles ◽  
Iron Particles ◽  
Magnetorheological Elastomer ◽  
Hard Magnetic Materials ◽  
Magnetorheological Elastomers ◽  
Cantilevered Beam ◽  
Magnetic Poles ◽  
New Generation

This study investigates a new generation of magnetorheological elastomers based on hard magnetic particles. Unlike traditional magnetorheological elastomers that use iron particles, a dispersion of hard magnetic materials aligned in an electromagnetic field will produce a magnetorheological elastomer with magnetic poles. When a magnetic field is applied, perpendicularly to these poles, the filler particles generate torque and cause rotational motion of the magnetorheological elastomer blend. The primary goal of this study is to fabricate and characterize the actuation properties of magnetorheological elastomers filled with various hard magnetic particles. To this end, samples of magnetorheological elastomers consisting of hard magnetic materials were fabricated using four different particle types, and a test setup (electromagnet) was constructed. After mounting the magnetically anisotropic samples in a fixed-free configuration, uniform magnetic fields are applied to the samples (perpendicular to the poled direction), which causes the sample to bend, similar to a cantilevered beam. The blocked force and tip displacement of the samples were measured to characterize actuation properties of the samples. The results show that the responses of the deflection and the blocked force at the tip show linear trends over a reasonable range, suggesting that magnetorheological elastomers consisting of hard magnetic materials can be used as bending-type actuators in small mechanical systems and devices.

Soft magnetorheological elastomers as new actuators for valves

2012 ◽  
Vol 23 (9) ◽  
pp. 989-994 ◽  
Author(s):  
Holger Böse ◽  
Raman Rabindranath ◽  
Johannes Ehrlich
Keyword(s):  
Magnetic Field ◽  
Magnetic Particles ◽  
Air Flow ◽  
Inhomogeneous Magnetic Field ◽  
Magnetorheological Elastomer ◽  
Magnetorheological Elastomers ◽  
Type Device ◽  
New Type ◽  
Flow Through ◽  
The Magnetic Field

The actuation behavior of soft silicone-based magnetorheological elastomers in magnetic fields of variable strength was investigated. An inhomogeneous magnetic field gives rise to a reversible actuation effect, which is the result of the competition between magnetic and elastic forces in the material. Magnetorheological elastomers are capable of performing more pronounced deformations than known rigid actuator materials. In this article, the actuation behavior of magnetorheological elastomer ring-shaped bodies in a valve-type device for the control of an air flow is demonstrated. For this purpose, magnetorheological elastomer rings with different Shore hardness were prepared and used in the valve. In addition to the common isotropic magnetorheological elastomer samples, rings with an anisotropic arrangement of the magnetic particles were also prepared. The actuation of these anisotropic magnetorheological elastomers was compared with that of the isotropic samples. Based on simulations, the inhomogeneity of the magnetic field at the magnetorheological elastomer material which is required for the actuation could be strongly affected by the shape in the design of the magnetic yoke. In this study, the closing characteristics of the valve with different yoke shapes and magnetorheological elastomer materials were evaluated by measuring the dependence of the air flow rate on the magnetic field strength. It is demonstrated that the air flow through the valve can be controlled by the current in the field-generating coil, which yields the base for a new type of magnetic valve.

The field-dependent complex modulus of magnetorheological elastomers consisting of sucrose acetate isobutyrate ester

2017 ◽  
Vol 28 (14) ◽  
pp. 1993-2004 ◽  
Author(s):  
Muntaz Hana Ahmad Khairi ◽  
Saiful Amri Mazlan ◽  
Ubaidillah ◽  
Ku Zarina Ku Ahmad ◽  
Seung-Bok Choi ◽  
...  
Keyword(s):  
Natural Rubber ◽  
Magnetic Particles ◽  
Complex Modulus ◽  
Excitation Frequency ◽  
Epoxidized Natural Rubber ◽  
Magnetorheological Elastomer ◽  
Magnetorheological Elastomers ◽  
Storage And Loss Moduli ◽  
The Matrix ◽  
Magnetorheological Effect

In this work, epoxidized natural rubber-50 magnetorheological elastomer was synthesized using conventional rubber processing. The ester plasticizer sucrose acetate isobutyrate was then incorporated into epoxidized natural rubber-50 to soften the matrix and to improve the relative magnetorheological effect. The influence of sucrose acetate isobutyrate ester on the microstructures and properties of epoxidized natural rubber-50 magnetorheological elastomers were experimentally investigated. It has been identified that the addition of sucrose acetate isobutyrate ester can reduce the viscosity of the matrix and increase the mobility of magnetic particles in a matrix. The elongation of magnetorheological elastomer was increased by 19%, and the tensile strength was reduced by 17% at 10 wt% content of the sucrose acetate isobutyrate ester. It is observed that the employment of sucrose acetate isobutyrate ester enhanced the thermal stability leading to low degradation of the properties of magnetorheological elastomer. In rheology test, both absolute and relative magnetorheological effects were increased by 0.16 MPa and 23%, respectively, with incorporation of the 7.5-wt% sucrose acetate isobutyrate ester. It is also identified that the storage and loss moduli as well as loss factor are increased as the excitation frequency is increased. It is finally concluded that agglomeration issues in isotropic magnetorheological elastomer which degrade performances of magnetorheological elastomer application devices and systems can be resolved by the addition of sucrose acetate isobutyrate ester to epoxidized natural rubber-50 used in this work.

The study of natural rubber/polybutadiene rubber hybrid matrix-based magnetorheological elastomer

2019 ◽  
pp. 089270571987822
Author(s):  
Xincheng Song ◽  
Wenju Wang ◽  
Fufeng Yang ◽  
Guoping Wang ◽  
Xiaoting Rui
Keyword(s):  
Energy Density ◽  
Natural Rubber ◽  
Cohesive Energy ◽  
Md Simulation ◽  
Magnetic Particles ◽  
Homogeneous System ◽  
Magnetorheological Elastomer ◽  
Cohesive Energy Density ◽  
Hybrid Matrix ◽  
Polybutadiene Rubber

Magnetorheological elastomer (MRE) that consists of matrix materials and magnetic particles is a kind of smart material, whose mechanical properties were controllable under external magnetic field. In this work, natural rubber (NR)/polybutadiene rubber (BR) hybrid matrix-based MRE was prepared. The compatibility of NR and BR was studied by experiment and molecular dynamic (MD) simulation. The hybrid matrix was prepared using the physical mixing method. The characterization results showed that BR had excellent compatibility with NR. The measurement result using rheometer showed that the MR effect can be increased to 44.19% by the addition of BR. Dynamic mechanical analysis showed that the hybrid matrix formed a homogeneous system when the ratio of BR and NR is 1:9 and 3:7. The MD simulation showed that the BR and NR are compatible and the cohesive energy density of hybrid matrix was smaller than BR and NR. The cohesive energy density of hybrid matrix was increased with the increase of BR.

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