Performance enhancement of an MRE-based isolator using a multi-layered electromagnetic system

Author(s):  
Yongmoon Hwang ◽  
Junghoon Lee ◽  
Seungkyung Kye ◽  
Hyung-Jo Jung

Abstract A magnetorheological elastomer (MRE) is one of smart materials which can control the stiffness according to a strength of a magnetic field. In this regard, various types of MRE-based isolators have been studies. However, there was a limit to performance validation due to the material and structural limitations. In this study, an optimal mixing ratio of the MRE was considered and a new type of an electromagnetic system was proposed. A multi-layered electromagnetic system was proposed to constantly maintain a magnetic closed circuit by behaving with the deformation of the MRE. Through this, numerical and experimental comparisons were performed with the conventional MRE-based isolator, and the superiority of the proposed MRE-based isolator was validated. Moreover, the dynamic characteristics of the proposed MRE-based isolator under the vertical load were investigated. The results show that the proposed MRE-based isolator outperforms the conventional MRE-based isolator in improving the MR effects and the dynamic characteristics of the proposed MRE-based isolator under the vertical load were identified.

2010 ◽  
Vol 37-38 ◽  
pp. 444-447 ◽  
Author(s):  
Wei Qiang Ye ◽  
Yi Min Deng ◽  
Wei Wang

As a new type of smart materials, magnetorheological elastomer (MRE) has become a hot current research focus. However, the piezoresistivity and magnetoresistivity of MRE have not been well studied. In this paper, this was done by using a test rig developed by the authors. The experimental results showed that the conductivity of the MRE responded sensitively to the applied pressure, and a linear relationship between the resistivity of the MRE and the applied pressure can be observed within a certain range. Besides, the sensitivity of piezoresistivity is different among different ratios of metal content, and it becomes more obvious when using the nickel content. And, the magnetoresistivity of MRE is not obvious in a range of low magnetic field intensity, and there is also no hysteresis phenomenon about magnetoresistivity.


2021 ◽  
Vol 11 (9) ◽  
pp. 4130
Author(s):  
Oleksij Fomin ◽  
Alyona Lovska ◽  
Václav Píštěk ◽  
Pavel Kučera

The study deals with determination of the vertical load on the carrying structure of a flat wagon on the 18–100 and Y25 bogies using mathematic modelling. The study was made for an empty wagon passing over a joint irregularity. The authors calculated the carrying structure of a flat wagon with the designed parameters and the actual features recorded during field tests. The mathematical model was solved in MathCad software. The study found that application of the Y25 bogie for a flat wagon with the designed parameters can decrease the dynamic load by 41.1% in comparison to that with the 18–100 bogie. Therefore, application of the Y25 bogie under a flat wagon with the actual parameters allows decreasing the dynamic loading by 41.4% in comparison to that with the 18–100 bogie. The study also looks at the service life of the supporting structure of a flat wagon with the Y25 bogie, which can be more than twice as long as the 18–100 bogie. The research can be of interest for specialists concerned with improvements in the dynamic characteristics and the fatigue strength of freight cars, safe rail operation, freight security, and the results of the research can be used for development of innovative wagon structures.


Author(s):  
Liu Ruiwei ◽  
Hongwei Guo ◽  
Zhang Qinghua ◽  
Rongqiang Liu ◽  
Tang Dewei

Balancing stiffness and weight is of substantial importance for antenna structure design. Conventional fold-rib antennas need sufficient weight to meet stiffness requirements. To address this issue, this paper proposes a new type of cable-rib tension deployable antenna that consists of six radial rib deployment mechanisms, numerous tensioned cables, and a mesh reflective surface. The primary innovation of this study is the application of numerous tensioned cables instead of metal materials to enhance the stiffness of the entire antenna while ensuring relatively less weight. Dynamic characteristics were analyzed to optimize the weight and stiffness of the antenna with the finite element model by subspace method. The first six orders of natural frequencies and corresponding vibration modes of the antenna structure are obtained. In addition, the effects of structural parameters on natural frequency are studied, and a method to improve the rigidity of the deployable antenna structure is proposed.


2018 ◽  
Vol 51 (7-8) ◽  
pp. 583-602
Author(s):  
Nabil Hayeemasae ◽  
Hanafi Ismail

This article proposes a new type of magnetorheological elastomer (MRE) based on natural rubber (NR) and waste natural rubber gloves (wNRg) blends. The material properties of the MRE samples were investigated with specific focus on the curing and swelling kinetics. Two different series were prepared; the first used carbonyl iron (CI) as the single filler in the MRE, whereas the second hybridized CI with carbon black (CB) to prepare an MRE resistant to solvents. The results show that most properties depend strongly on the nature of both fillers. The higher thermal conductivity of the CI caused a substantial decrease in both the scorch and curing times and the activation energy in the curing process. Based on the diffusion study, a higher volume of fillers in the rubber composites resulted in a greater area of blockage and restricted the penetration of the solvent tested throughout the composites, irrespective of whether CI alone or in combination with CB was used in the composites.


2020 ◽  
Vol 70 (1) ◽  
pp. 41-46
Author(s):  
Yaoji Deng ◽  
Youqun Zhao ◽  
Mingmin Zhu ◽  
Zhen Xiao ◽  
Qiuwei Wang

To overcome the shortcomings of traditional rigid road wheel, such as poor damping effect and low load-bearing efficiency, a new type of flexible road wheel, having a unique suspension-bearing mode, was introduced. The three-dimensional nonlinear finite element model of rigid and flexible road wheel, considering the triple nonlinear characteristics of geometry, material and contact, is established for numerical investigation of static loading performance. The accuracy of the finite element model of the rigid and flexible road wheel is verified by static loading experiment. The static loading performance of the rigid and flexible road wheels is numerically analyzed. The influence of vertical load on maximum stress and deformation of the rigid and flexible wheels is also studied. The results show that the contact pressure uniformity of the flexible road wheel is better than that of the rigid road wheel under the static vertical load, but the maximum stress and deformation of the flexible road wheel are greater than that of the rigid road wheel. However, this problem can be solved by increasing the number of hinge sets and optimising the joints. The research results provide theoretical basis for replacing rigid road wheel with flexible road wheel, and also provide reference for structural optimisation of flexible road wheel.


Materials ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 3017 ◽  
Author(s):  
Sneha Samal ◽  
Marcela Škodová ◽  
Ignazio Blanco

The smart materials subclass of magnetorheological elastomer (MRE) composites is presented in this work, which aimed to investigate the influence of filler distribution on surface morphology. Iron particles with sizes ranging from 20 to 150 µm were incorporated into the elastomer matrix and a 30% volume fraction (V%) was chosen as the optimal quantity for the filler amount in the elastomer composite. The surface morphology of MRE composites was examined by 3D micro-computed tomography (µCT) and scanning electron microscopy (SEM) techniques. Isotropic and anisotropic distributions of the iron particles were estimated in the magnetorheological elastomer composites. The filler particle distribution at various heights of the MRE composites was examined. The isotropic distribution of filler particles was observed without any influence from the magnetic field during sample preparation. The anisotropic arrangement of iron fillers within the MRE composites was observed in the presence of a magnetic field during fabrication. It was shown that the linear arrangement of the iron particle chain induced magnetization within the composite. Simulation analysis was also performed to predict the particle distribution of magnetization in the MREs and make a comparison with the experimental observations.


2014 ◽  
Vol 1022 ◽  
pp. 26-29
Author(s):  
Yong Hui Jia ◽  
Jia Xiao Heng

In this paper, the piezoelectric ceramic crisp, poor water resistance, resistance to external load capability is not strong lack of self-designed package more perfect a new type of "smart piezoelectric aggregate", to better address the PZT film resist unfavorable load , vulnerability and durability issues and other aspects; and further superior characteristics of piezoelectric smart sensing and drive integration of theoretical analysis, modeling, numerical calculations, mechanical analysis and experimental research; on this basis, based on the pressure and Experimental Research aggregate electric smart sensor / driver structural health monitoring and damage detection algorithm, the theoretical basis for the realization of the transition from the pilot study engineering applications to provide the experimental basis and technical support.


2011 ◽  
Vol 90-93 ◽  
pp. 1351-1354
Author(s):  
Xiao Yan Lin ◽  
Tong Lu Li

The conventional shear creep apparatus uses lever to amplify the load, which has a serious limitations in practical use. First, the round and small shearing box can easily form an obvious stress concentration in the margin area. In addition, tilting of the lever can give an unreal vertical load in loading process. Aiming to solve the shortages of conventional apparatus, a new type of shear creep apparatus is introduced in this paper, whose loading system apply the pulley block, and shear box is changed from the round with the area of 30cm2 into the present square one with 10×10cm2. The new shear creep apparatus has more advantage compared with the conventional, and is more satisfactory to the need of test.


2012 ◽  
Vol 588-589 ◽  
pp. 1960-1963
Author(s):  
Yun Long Yao ◽  
Guang Ying Ma ◽  
Shi Lin Dong

The large-span space beam string-structure system is a kind of economic and larger spanning spatial structure system. A new type of space beam-string-structure with outer truss torus is introduced. Sunflower-patterned space beam-string-structure was taken as an example and its dynamic characteristics under full-span load and half-span load were analyzed by block Lanczos method. The efect of prestress level and load level on dynamic behavior of the structure was studied. The results are valuable for the dynamic response research on the earthquakes and wind vibration and will provide a reference for a further design and project application of such structure.


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