Influence of interparticle friction on the magneto-rheological effect for magnetic fluid: a simulation investigation

2020 ◽  
Vol 29 (11) ◽  
pp. 115002
Author(s):  
Lei Pei ◽  
Shouhu Xuan ◽  
Haoming Pang ◽  
Xinglong Gong
Machines ◽  
2019 ◽  
Vol 7 (2) ◽  
pp. 36 ◽  
Author(s):  
Renato Brancati ◽  
Giandomenico Di Massa ◽  
Stefano Pagano

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.


2012 ◽  
Vol 110 (13) ◽  
pp. 1429-1435 ◽  
Author(s):  
Yasuhiro Sakuda ◽  
Masayuki Aoshima ◽  
Akira Satoh

Soft Matter ◽  
2021 ◽  
Author(s):  
Xiao Liu ◽  
Decai Li

In this paper, we study the effect of hydrophilic fumed silica nanoparticles with different mass fraction on the magneto-rheological properties of magnetic fluid, and reveal the mechanism by the coarse-grained...


2014 ◽  
Vol 620 ◽  
pp. 288-296
Author(s):  
Hang Song Yang ◽  
Peng Li ◽  
Li Zhi Gu ◽  
Hui Juan Guo

In this paper, turn the medium of magneto rheological liquid into continuation, and using of the critical Reynolds number determine method of liquid move state and compound with non-Newton fluid, get the conclusion of finished machine abrasive magnetic liquid fluid as laminar fluid, for having no mathematics’ model practical or be fit with the experiment, especially the distribution of shear and velocity stress, In this paper, using of the critical Reynolds number to determine the liquid state of magnetic fluid state, and in determined the fluid state, using non-Newton fluid dynamics and tensor analysis theory and also compound with the double dynamic viscosity model, analysis the abrasive magnetic fluid quality of kinematics shear stress, according to the quality, contracture the dynamic model of abrasive magnetic liquid finished machine, during the interfere, using the double viscosity fluid model, we may get the conclusion, liquid magnetic abrasive, when the shear stress more or less the bend stress, and mark with plasticity viscosity ηp0, ηpγ which round the work piece center, the velocity distribution as laminar, and also, analysis the flow field mathematics’ model by the finite element, and also going on the numerical simulate for the magnetic fluid velocity field of finished machine.


Author(s):  
Rafael Cuadra ◽  
Akira Satoh

In a suspension composed of spindle-like hematite particles (α-Fe2O3), the previous theoretical study based on the orientational distribution function has shown that the viscosity due to the magnetic properties of spindle-like hematite particles exhibits negative magneto-rheological characteristics in a certain situation of the orientational distribution of the particles under a certain applied magnetic field circumstance. This is mainly because the spindle-like hematite particles have a unique characteristic in that they are magnetized in a direction normal to the particle axis direction. This weak magnetic characteristic yields an advantage to the suspension in that it is relatively straightforward to synthesize a stable dispersion of such hematite particles because the electric double layer functions well for preventing the particles from aggregating. The negative magneto-rheological effect has also energetically been investigated by a simulation approach based on the Brownian dynamics and these simulation results clearly show that the negative magneto-rheological characteristics certainly arise in a multi-particle suspension system. From this background, in the previous experimental study, we synthesized a suspension composed of spindle-like hematite particles and measured the viscosity due to the magnetic properties of the particles in a simple shear flow. This first simple experiment has succeeded in verifying that the negative magneto-rheological characteristics surely arise in an actual hematite particle suspension. The present study further advances the experimental investigation of the negative magneto-rheological effect in order to obtain the more detailed data of these negative magneto-rheological characteristics. The viscosity due to the magnetic properties was measured using a cone-plate-type rheometer, located in the uniform area of the magnetic field, under various conditions of the magnetic field strength and the shear rate of a shear flow. The viscosity of hematite-glycerol-water dispersions becomes negative, attains to a minimum value, after that starts to increase, and finally becomes positive with increasing magnetic field strength. These characteristics of the negative viscosity are in good agreement with the theoretical prediction that was obtained by the orientational distribution function.


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