Fabrication and Mechanical Properties Study of the Magnetorheological Elastomer

2013 ◽  
Vol 376 ◽  
pp. 148-152 ◽  
Author(s):  
Guang Hui Li ◽  
Xue Gong Huang ◽  
Xiao Yu Gu ◽  
Jiong Wang
Keyword(s):  
Magnetic Field ◽  
Mechanical Properties ◽  
Permanent Magnets ◽  
Variable Stiffness ◽  
Test System ◽  
Magnetorheological Elastomer ◽  
Preparation Methods ◽  
Operating Modes ◽  
Close Form ◽  
Stiffness Loss

Magnetorheological elastomer (MRE) is a novel kind of magnetorheological materials and has been successfully used to control the structure vibration due to its property of variable stiffness under different magnetic field. In order to improve the properties of MRE, it urgently needs to investigate the preparation methods of MRE and build a corresponding test system to evaluate the performance of MRE in different operating modes. In this paper, different magnetic devices for preparing MRE were studied and designed, and the material was fabricated by the permanent magnets with additional permeability equipment at last. Then, according to the SDOF principle, a novel test system was built in order to investigate the mechanical properties of MRE, and exact close-form expressions of the stiffness, loss factor and other mechanical parameters of MRE, under different magnetic field, have been calculated to analyze the properties of MRE.

scholarly journals Homopolymer Based Magnetorheological Elastomer

2021 ◽  
pp. 54-57
Author(s):  
Parth Dhrangdhariya ◽  
Sunil Padhiyar ◽  
Prince Mishra
Keyword(s):  
Magnetic Field ◽  
Mechanical Properties ◽  
Vibration Control ◽  
Applied Magnetic Field ◽  
Variable Stiffness ◽  
Rubber Matrix ◽  
Vibration Absorber ◽  
Vibration Isolator ◽  
Magnetorheological Elastomer ◽  
Spring Force

Magnetorheological rubber belongs to the class of ‘Smart Material’ whose mechanical properties can be altered continuously and reversibly by an applied magnetic field. Magnetorheological rubber (MRE’s) are composites that consists of magnetically polarisable particles mixed into rubber matrix. With suitable controlled algorithms, they respond to change in their environment. Purpose of this work is to know more about magnetorheological rubber for active stiffness, vibration control and dampening applications. Although few applications of these materials have been reported in the literature, the possibilities are numerous. They can be used for various applications such as vibration absorber, vibration isolator, variable stiffness bush, spring, force sensors, actuators etc.

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.

A study of the magnetic fatigue properties of a magnetorheological elastomer

2018 ◽  
Vol 30 (5) ◽  
pp. 749-754 ◽  
Author(s):  
Chenglong Lian ◽  
Kwang-Hee Lee ◽  
Seung-Bok Choi ◽  
Chul-Hee Lee
Keyword(s):  
Magnetic Field ◽  
Mechanical Properties ◽  
Shear Modulus ◽  
Internal Structure ◽  
Fatigue Properties ◽  
Fatigue Cycle ◽  
Repeated Application ◽  
Magnetorheological Elastomer ◽  
Before And After ◽  
Microscopy Images

In this study, the magnetic fatigue properties of a magnetorheological elastomer were evaluated with and without a magnetic field. To accomplish the process, a magnetic fatigue tester and magnetorheological elastomer samples were designed and fabricated. The mechanical properties of the magnetorheological elastomer were determined under various fatigue cycle numbers and fatigue frequencies with and without a magnetic field. The shear modulus of the magnetorheological elastomer was also measured before and after the test to evaluate its mechanical properties. The results show that the shear modulus of the magnetorheological elastomer was larger in the presence of a magnetic field and decreased as the number of fatigue cycles increased because the internal structure became loose. Scanning electron microscopy images showed that the internal structure of the magnetorheological elastomer was loose under repeated application of magnetic fields.

scholarly journals STUDY OF ELASTIC PROPERTIES OF A MAGNETO-RHEOLOGICAL ELASTOMER FOR VIBRO-INSULATION IN VACUUM

2020 ◽  
Vol 6 (1) ◽  
pp. 43-47
Author(s):  
A. M. Bazinenkov ◽  
D. A. Ivanova ◽  
I. A. Efimov ◽  
A. P. Rotar
Keyword(s):  
Magnetic Field ◽  
Mechanical Properties ◽  
Composite Material ◽  
Vibration Isolation ◽  
Magnetorheological Elastomer ◽  
Correct Operation ◽  
Active Vibration ◽  
Magneto Rheological ◽  
Increasing Temperature ◽  
Damping Systems

Magnetorheological elastomer is used in vibration isolation and damping systems; it is promising to use a platform of active vibration isolation in a vacuum to provide vibration protection for the research object. Polymer is a composite material whose rheological properties can change under the influence of a directed magnetic field. For the correct operation of the platform, the constancy of mechanical properties is necessary, which can change during degassing with increasing temperature. The paper presents the results of studies of the mechanical properties of MRE with various compositions prior to degassing in a vacuum. It was found that the elastic modulus of the polymer directly depends on the concentration of filler particles, and no dependence on the presence of surfactants was found.

Cellulose Nanofibrils-based Hydrogels for Biomedical Applications: Progresses and Challenges

2020 ◽  
Vol 27 (28) ◽  
pp. 4622-4646 ◽  
Author(s):  
Huayu Liu ◽  
Kun Liu ◽  
Xiao Han ◽  
Hongxiang Xie ◽  
Chuanling Si ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Metal Ion ◽  
Biomedical Applications ◽  
Biomedical Application ◽  
Cellulose Nanofibrils ◽  
Wound Dressings ◽  
Preparation Methods ◽  
Tissue Scaffold ◽  
Surface Areas ◽  
Mechanical Methods

Background: Cellulose Nanofibrils (CNFs) are natural nanomaterials with nanometer dimensions. Compared with ordinary cellulose, CNFs own good mechanical properties, large specific surface areas, high Young's modulus, strong hydrophilicity and other distinguishing characteristics, which make them widely used in many fields. This review aims to introduce the preparation of CNFs-based hydrogels and their recent biomedical application advances. Methods: By searching the recent literatures, we have summarized the preparation methods of CNFs, including mechanical methods and chemical mechanical methods, and also introduced the fabrication methods of CNFs-based hydrogels, including CNFs cross-linked with metal ion and with polymers. In addition, we have summarized the biomedical applications of CNFs-based hydrogels, including scaffold materials and wound dressings. Results: CNFs-based hydrogels are new types of materials that are non-toxic and display a certain mechanical strength. In the tissue scaffold application, they can provide a micro-environment for the damaged tissue to repair and regenerate it. In wound dressing applications, it can fit the wound surface and protect the wound from the external environment, thereby effectively promoting the healing of skin tissue. Conclusion: By summarizing the preparation and application of CNFs-based hydrogels, we have analyzed and forecasted their development trends. At present, the research of CNFs-based hydrogels is still in the laboratory stage. It needs further exploration to be applied in practice. The development of medical hydrogels with high mechanical properties and biocompatibility still poses significant challenges.

scholarly journals Design of a New 1D Halbach Magnet Array with Good Sinusoidal Magnetic Field by Analyzing the Curved Surface

Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2522
Author(s):  
Guangdou Liu ◽  
Shiqin Hou ◽  
Xingping Xu ◽  
Wensheng Xiao
Keyword(s):  
Magnetic Field ◽  
Magnetic Flux ◽  
Permanent Magnet ◽  
Flux Density ◽  
Permanent Magnets ◽  
Air Gap ◽  
Curved Surface ◽  
Magnetic Flux Density ◽  
Sinusoidal Magnetic Field ◽  
The Magnetic Field

In the linear and planar motors, the 1D Halbach magnet array is extensively used. The sinusoidal property of the magnetic field deteriorates by analyzing the magnetic field at a small air gap. Therefore, a new 1D Halbach magnet array is proposed, in which the permanent magnet with a curved surface is applied. Based on the superposition of principle and Fourier series, the magnetic flux density distribution is derived. The optimized curved surface is obtained and fitted by a polynomial. The sinusoidal magnetic field is verified by comparing it with the magnetic flux density of the finite element model. Through the analysis of different dimensions of the permanent magnet array, the optimization result has good applicability. The force ripple can be significantly reduced by the new magnet array. The effect on the mass and air gap is investigated compared with a conventional magnet array with rectangular permanent magnets. In conclusion, the new magnet array design has the scalability to be extended to various sizes of motor and is especially suitable for small air gap applications.

scholarly journals Preparation of Electric- and Magnetic-Activated Water and Its Influence on the Workability and Mechanical Properties of Cement Mortar

2021 ◽  
Vol 13 (8) ◽  
pp. 4546
Author(s):  
Kaiyue Zhao ◽  
Peng Zhang ◽  
Bing Wang ◽  
Yupeng Tian ◽  
Shanbin Xue ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Mechanical Properties ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Cement Paste ◽  
Cement Mortar ◽  
Environmental Issues ◽  
Chemical Admixtures ◽  
Untreated Water ◽  
Alternating Voltage

Cement-based materials prepared with activated water induced by a magnetic field or electric field represent a possible solution to environmental issues caused by the worldwide utilization of chemical admixtures. In this contribution, electric- and magnetic-activated water have been produced. The workability and mechanical properties of cement mortar prepared with this activated water have been investigated. The results indicate that the pH and absorbance (Abs) values of the water varied as the electric and magnetic field changed, and their values increased significantly, exhibiting improved activity compared with that of the untreated water. In addition, activated water still retains activity within 30 min of the resting time. The fluidity of the cement paste prepared with electric-activated water was significantly larger than that of the untreated paste. However, the level of improvement differed with the worst performance resulting from cement paste prepared with alternating voltage activated water. In terms of mechanical properties, both compressive strength and flexural strength obtained its maximum values at 280 mT with two processing cycles. The compressive strength increased 26% as the curing time increased from 7 days to 28 days and flexural strength increased by 31%. In addition, through the introduction of magnetic-activated water into cement mortar, the mechanical strength can be maintained without losing its workability when the amount of cement is reduced.

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