scholarly journals Research on chain-model transition identification of magnetic dipole theory for magneto-rheological fluid

2016 ◽  
Vol 8 (12) ◽  
pp. 168781401668363 ◽  
Author(s):  
Xiaomin Dong ◽  
Chi Duan ◽  
Jianqiang Yu

Chain formation model is very useful to characterize the magneto-rheological phenomenon and prepare good magneto-rheological fluids. The single-chain model is common to explain the process of chain formation for ferromagnetic particles under magnetic field. With the increment of magnetic field and ferromagnetic particle content, the chain will transit from the single chain to multi-chains. However, there are few literatures involved in this phenomenon. This study investigates the effect of magnetic field and ferromagnetic particles content on the transition. The static yield stresses at different magnetic fields were measured under quasi-static mode for different magneto-rheological fluid samples. The results show that the transition of chain model can be identified on two parameters including the amplitude of static yield angle, [Formula: see text], and the inclined angles distribution, [Formula: see text]. The single-chain model is only effective under low magnetic field and ferromagnetic particles below content of 30% volume. With the increment of magnetic field and ferromagnetic particles content, the transition from single chain to multiple chains will be observed, which validates that there is a transition from the single chain to multi-chains.

2007 ◽  
Vol 546-549 ◽  
pp. 1673-1676 ◽  
Author(s):  
Wei Jia Meng ◽  
Zhan Wen Huang ◽  
Yan Ju Liu ◽  
Xiao Rong Wu ◽  
Yi Sun

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.


Author(s):  
Xiaojie Wang ◽  
Faramarz Gordaninejad ◽  
Mert Calgar ◽  
Yanming Liu ◽  
Joko Sutrisno ◽  
...  

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.


2013 ◽  
Vol 542 ◽  
pp. 11-27 ◽  
Author(s):  
Marek Barski ◽  
Małgorzata Chwał ◽  
Piotr Kędziora

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.


2020 ◽  
Vol 64 (1-4) ◽  
pp. 439-446
Author(s):  
Gildas Diguet ◽  
Gael Sebald ◽  
Masami Nakano ◽  
Mickaël Lallart ◽  
Jean-Yves Cavaillé

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.


2021 ◽  
pp. 251659842110157
Author(s):  
Chinu Kumari ◽  
Sanjay Kumar Chak

Magneto-rheological abrasive honing (MRAH) is an unconventional surface finishing technique that relies on abrasives mixed with a unique finishing fluid, which changes its characteristics on magnetic field application. This process imparts nanometric-level surface finish with a significant amount of uniformity. Rotating motion of the workpiece and continuous reciprocation of the finishing fluid in the MRAH process are recognized as the major aspects for adopting this process in finishing non-magnetic materials. The finishing obtained through the MRAH process relies on the workpiece’s material properties and process parameters such as concentration of abrasives in finishing fluid, rotational speed of the workpiece, and magnetic field strength/magnetizing current. To study the efficacy of MRAH process, a parametric study was conducted by performing few experiments on a brass workpiece. Design of experiment approach was adopted to plan the experiments, and the effect of different values of magnetizing current, the concentration of abrasives, and rotational speed on the surface finish were analyzed through the application of analysis of variance (ANOVA). From ANOVA, the rotational speed was found as the most significant parameter with a contribution of 48.90% on % reduction in roughness value (%∇Ra). Around 57% of roughness reduction was obtained at the optimized value of process parameters.


2016 ◽  
Vol 30 (25) ◽  
pp. 1650183 ◽  
Author(s):  
Yu. N. Ovchinnikov

The effect of spin-orbit (SO) interaction on the formation of the critical states in thin superconducting films in magnetic field oriented along the film is investigated. Hereby, the case of interband pairing is considered. It was found that eight branches exist in the plane of two parameters [Formula: see text] determined by the value of magnetic field and SO interaction. Six modes leads to inhomogeneous states with different values of the impulse [Formula: see text]. Each state is doubly degenerate over direction of impulse [Formula: see text]. The parameter values at critical point are found for all eight branches in explicit form for zero temperature. The optimal two branches are estimated, corresponding to largest critical magnetic field value for given SO interaction.


2012 ◽  
Vol 430-432 ◽  
pp. 1979-1983
Author(s):  
Wei Bang Feng ◽  
Xue Yang ◽  
Zhi Qiang Lv

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.


Sign in / Sign up

Export Citation Format

Share Document