Study on the Magnetic Field‐Dependent Rolling Friction Coefficient Compensation of Magnetorheological Elastomer (MRE)‐Copper Ball Friction Pair with Wet Interfaces

Author(s):  
Rui Li ◽  
Xin Gou ◽  
Xinyan Li ◽  
Ping-an Yang ◽  
Dan Feng ◽  
...  
2017 ◽  
Vol 139 (5) ◽  
Author(s):  
Chenglong Lian ◽  
Kwang-Hee Lee ◽  
Chul-Hee Lee

Magnetorheological elastomers (MREs) are smart materials that have been studied widely for their material properties. The elasticity modulus or hardness of an MRE can be changed when an external magnetic field is applied. In this study, a study of MREs applied to rolling friction control under various external magnetic strengths is conducted. To accomplish this, the rolling friction property of an elastomer on a rigid plate is analyzed. Then, MREs are prepared, and a rolling friction tester is designed to evaluate the changes in the rolling friction coefficient. The results show that the rolling friction coefficient can be changed with different magnetic field strengths. The rolling friction coefficient of the MRE can be controlled by the applied magnetic field, which can be applied to control the slip rate and be adapted to achieve the optimal friction effect in the future.


2021 ◽  
Vol 143 (12) ◽  
Author(s):  
Chenglong Lian ◽  
Kwang-Hee Lee ◽  
Chul-Hee Lee ◽  
Yongfeng Li ◽  
Peng Zhang

Abstract Magnetorheological elastomers (MREs) are smart materials whose stiffness and shear modulus can be changed by applying an external magnetic field. They can be used in various ways. This experimental study looks at the rolling friction coefficient controllability of MREs. MRE samples were manufactured, and their rolling friction properties were measured by a rolling friction test, in which the input magnetic field strengths and rolling speed can be adjusted. Various speed conditions were applied to find the rolling friction properties under different applied magnetic field strengths. The rolling friction coefficient and slip rate control under a magnetic control were then analyzed. The results show that the rolling friction coefficient can be adjusted at different rolling slip rates by the application of a magnetic field, which can increase the rolling friction coefficient range in the control system of the rolling friction coefficient and slip rate. Based on the results of this research, MREs could someday be used in antilock brake systems as a stiffness-control material when a controlled magnetic field is applied, and the rolling friction efficiency could be increased.


2021 ◽  
Vol 1037 ◽  
pp. 141-147
Author(s):  
Andrey Minaev ◽  
Juri Korovkin ◽  
Hammat Valiev ◽  
G.V. Stepanov ◽  
Dmitry Yu. Borin

Experimental studies magnetorheological elastomer specimens dynamic properties under the magnetic fields action on the vibrostend are carried out. Amplitude-frequency characteristics have been obtained. The magnetic field effect on the silicone magnetoreactive elastomers deformation properties and damping coefficients experimentally is established.


Processes ◽  
2020 ◽  
Vol 8 (7) ◽  
pp. 853 ◽  
Author(s):  
Yu Huang ◽  
Jian Ruan ◽  
Chenchen Zhang ◽  
Chuan Ding ◽  
Sheng Li

Since many studies on axial piston pumps aim at enhancing their high power-weight ratio, many researchers have focused on the generated mechanical losses by the three friction pairs in such pumps and attempted to diminish them through abundant and new structural designs of the pump’s components. In this paper, a high-speed 2D piston pump is introduced and its architecture is specifically described. Afterward, a mathematical model is established to study the pump’s mechanical efficiency, including the mechanical losses caused by the viscosity and stirring oil. Additionally, in this study the influences of the rotational speed, the different load pressures, and the rolling friction coefficient between the cone roller and the guiding rail are considered and discussed. By building a test rig, a series of experiments were carried out to prove that the mechanical efficiency was accurately predicted by this model at low load pressures. However, there was an increasing difference between the test results and the analytical outcomes at high pressures. Nevertheless, it is still reasonable to conclude that the rolling friction coefficient changes as the load pressure increases, which leads to a major decrease in the mechanical efficiency in experiments.


2008 ◽  
Vol 6 (3) ◽  
pp. 195-197 ◽  
Author(s):  
刘婷 Ting Liu ◽  
陈险峰 Xianfeng Chen ◽  
狄子昀 Ziyun Di ◽  
张军锋 Junfeng Zhang ◽  
李新碗 Xinwan Li ◽  
...  

The diamagnetism of free electrons in the presence of charged impurity centres which are sufficiently dilute to be non-interacting is calculated to first order in the strength of the potential of the impurity centre. This is done by combining the density-matrix treatment of Landau diamagnetism with the impurity-screening theory o f March & Murray. The susceptibility involves the integrated value of the impurity potential through the crystal, and its first derivative with respect to the magnetic field, B. If the impurity potential is assumed to have a value appropriate to B — 0, then the result for the change in diamagnetic susceptibility on alloying agrees with that of Kohn & Luming (1963). It is shown, however, that the impurity potential is modified in the presence of the magnetic field, and in particular it has angular dependence. The correction to the dia­magnetic susceptibility due to this self-consistency is shown to be significant (25% ). The relevance of the theory to experimental results on dilute alloys is briefly discussed. Finally, as a by-product of the investigation, we have obtained interesting results about the form of the field-dependent dielectric constant.


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