Design and application of an improved vulcanization apparatus for magnetorheological elastomer

2020 ◽  
Vol 31 (14) ◽  
pp. 1676-1688
Author(s):  
Lili Fan ◽  
Guoping Wang ◽  
Fufeng Yang ◽  
Min Jiang ◽  
Xiaoli Dong ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Heat Dissipation ◽  
Circuit Simulation ◽  
Experimental Tests ◽  
Control Device ◽  
Control Area ◽  
Magnetorheological Elastomer ◽  
Consistency Test ◽  
Promising Application ◽  
Magnetic Field Generator

Magnetorheological elastomer is a new intelligent material, which shows a promising application prospect in the intelligent control area. In the molding of magnetorheological elastomer, vulcanization under magnetic field condition is the critical step. However, the traditionally used vulcanization apparatus cannot be applied in the preparation of magnetorheological elastomer directly for the unavailable magnetic field, uneven pressure, and serious heat dissipation. An improved vulcanization apparatus with magnetic field generator, support device, and temperature control device was designed. To ensure the rationality of the designs, magnetic circuit simulation, thermal simulation, and stiffness consistency test were conducted. Experimental tests showed that the vulcanization apparatus we designed applied well in the preparation of magnetorheological elastomers and magnetorheological elastomer isolator.

Design of a stiffness variable flexible coupling using magnetorheological elastomer for torsional vibration reduction

2019 ◽  
Vol 30 (15) ◽  
pp. 2212-2221 ◽  
Author(s):  
Kang-Hyun Lee ◽  
Jae-Eun Park ◽  
Young-Keun Kim
Keyword(s):  
Magnetic Field ◽  
Torsional Vibration ◽  
Dynamic Stiffness ◽  
Torsional Stiffness ◽  
Magnetorheological Elastomer ◽  
Dynamic Disturbance ◽  
Flexible Coupling ◽  
Base Matrix ◽  
Stiffness Variation ◽  
Magnetic Field Generator

In this study, the design of an magnetorheological elastomer flexible coupling whose torsional stiffness can be controlled by an embedded magnetic field generator is proposed. It is designed to minimize the torsional vibration transmission between shafts adaptively to the dynamic disturbance. The coupling insert is composed of magnetorheological elastomer which is a smart material whose stiffness can be controlled by an external magnetic field. This article also proposes a compact magnetic field generator which can be fitted inside the coupling hubs, to control the torsional stiffness of the magnetorheological elastomer. The finite element method was used to design and estimate the dynamic stiffness variation of the magnetorheological elastomer coupling due to the applied magnetic field and disturbance frequency. Also, torsional vibration experiments were conducted to validate the performance of the proposed magnetorheological elastomer coupling. Results showed that it can adaptively tune in a range of frequencies between 16.8 and 23.5 Hz and has 95.7% stiffness variation under magnetic field of 150mT. The proposed system is expected to achieve a higher MRE effect with a softer base matrix.

A Repeated Pulsed High Magnetic Field Generator for Frequency-Tunable Terahertz Sources

2012 ◽  
Vol 516-517 ◽  
pp. 1897-1901 ◽  
Author(s):  
Huan Li ◽  
Hong Fa Ding ◽  
Hou Xiu Xiao
Keyword(s):  
Magnetic Field ◽  
High Magnetic Field ◽  
Heat Dissipation ◽  
Pulse Repetition Frequency ◽  
Terahertz Sources ◽  
In Series ◽  
Gate Driver ◽  
Frequency Tunable ◽  
Magnetic Field Generator ◽  
Pulsed High Magnetic Field

This paper presents a Repeated Pulsed High Magnetic Field (RPHMF) generator for frequency-tunable terahertz sources, which mainly consists of a charging power supply, a capacitor bank, a discharging switch, a bitter magnet and other facilities. The four thyristors (80 mm, 4 kV) in series with a self-supplied gate driver are taken as the discharge switch which can be triggered when the high voltage capacitor C was charged to 300 V. Meanwhile, a bitter magnet with fast heat dissipation was designed and fabricated. According to the experiment, the designed system has a pulse repetition frequency of 0.1 Hz with a maximum magnetic field of 9 T.

scholarly journals A new magnetorheological elastomer torsional vibration absorber: structural design and performance test

2021 ◽  
Vol 12 (1) ◽  
pp. 321-332
Author(s):  
Pu Gao ◽  
Hui Liu ◽  
Changle Xiang ◽  
Pengfei Yan ◽  
Taha Mahmoud
Keyword(s):  
Magnetic Field ◽  
Torsional Vibration ◽  
Performance Test ◽  
Magnetic Circuit ◽  
Circuit Simulation ◽  
Variable Stiffness ◽  
Vibration Absorber ◽  
Vibration Exciter ◽  
Magnetorheological Elastomer ◽  
The Magnetic Field

Abstract. The semi-active torsional vibration absorber can effectively reduce the torsional vibration of the power-train system. In this paper, a new type of variable stiffness torsional vibration absorber with a magnetorheological elastomer (MRE) as an intelligent controlling element is designed, and the modal analysis, frequency-tracking scheme, and damping effects have been studied. A transient dynamic simulation is utilized to validate the rationality of the mechanical structure, the magnetic field parameters of the absorber are matched, and the magnetic circuit simulation analysis and the magnetic field supply analysis are carried out to verify the closed magnetic circuit. The principle prototype of the innovative vibration absorber is manufactured, the magnetic field strength of the absorber is tested by a Gauss meter, and the results show the efficacy of magnetizing the vibration absorber with a conductive slip ring by solving the magnetizing problem of the rotating parts of the vibration absorber. A special-purpose test rig with a torsional vibration exciter as a power source has been implemented. A comparative experiment has been carried out to test the frequency shift characteristics and authenticate the vibration-reduction effect of the new MRE torsional vibration absorber.

Modelling and experimental characterisation of a compressional adaptive magnetorheological elastomer isolator

2021 ◽  
pp. 107754632110253
Author(s):  
Emiliano Rustighi ◽  
Diego F Ledezma-Ramirez ◽  
Pablo E Tapia-Gonzalez ◽  
Neil Ferguson ◽  
Azrul Zakaria
Keyword(s):  
Magnetic Field ◽  
Silicone Rubber ◽  
Magnetic Interaction ◽  
Iron Particle ◽  
Material Model ◽  
Rubber Matrix ◽  
Magnetorheological Elastomer ◽  
Volume Percentage ◽  
Shock Absorbers ◽  
Percent Concentration

This article proposes a simple physical-based model to describe and predict the performance of axially compressed magnetorheological elastomer cylinders used as vibration and shock absorbers. The model describes the magnetorheological elastomer macroscopic stiffness changes because of an externally applied magnetic field from a microscopic composite cell of silicone rubber and carbonyl iron particle. Despite neglecting the material hyperelasticity, anisotropy and adjacent magnetic interaction, the model describes effectively the effect of the magnetic field on the macroscopic modulus of elasticity. The changes in the mechanical properties with the induced magnetic field are measured on samples of different particle concentration based on volume percentage, that is, 10 and 30 percent concentration of iron particles in a silicone rubber matrix. The manufacturing process of the samples is detailed, as well as the experimental validation of the effective stiffness change under a magnetic field in terms of transmissibility and mobility testing. However, the prediction seems to be limited by the linear elastic material model. Predictions and measurements are compared, showing that the model is capable of predicting the tunability of the dynamic/shock absorber and that the proposed devices have a possible application in the reduction of mechanical vibrations.

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