A Novel Chain-Cluster Model of Magnetorheological Elastomer for the Dynamic Mechanical Performance Research

2021 ◽  
Author(s):  
Lili Fan
Keyword(s):  
Cluster Model ◽  
Mechanical Performance ◽  
Volume Fraction ◽  
Particle Volume Fraction ◽  
Dynamic Mechanical Properties ◽  
Magnetorheological Elastomer ◽  
Particle Volume ◽  
Microscopic Mechanism ◽  
Dynamic Mechanical ◽  
Response Characteristics

Abstract The existing research on magnetorheological elastomer (MRE) mainly focused on the improvement of MRE formula and structural design of MRE devices. As to the microscopic mechanism, less research has been done. Based on the scanning electron micrograph (SEM) of MRE, a novel chain-cluster model of MRE was constructed in this study. Particle size and particle distance were introduced simultaneously to the constitutive relation of MRE. The dynamic mechanical properties of MRE are studied theoretically and experimentally. Using the constructed chain-cluster model of MRE, the effect of magnetic field, particle volume fraction and strain on the magnetic-induced modulus of MRE were simulated. Rotating rheometer was adopted to test the magnetic response characteristics of MREs. Simulation and test results showed that the maximum magnetic-induced modulus tested experimentally was in good agreement with that calculated theoretically. Thus, the constructed chain-cluster model of MRE shows an important role in the field of intelligent vibration. It not only makes great sense in the prediction of MRE property but provides guidance on the property improvement of MRE.

scholarly journals Microstructure-based modeling of the dynamic mechanical properties of SiCp/Al composites

2016 ◽  
Vol 23 (4) ◽  
pp. 363-366
Author(s):  
Mei Ni Yuan ◽  
Yan Qing Yang ◽  
Qiao Juan Gong ◽  
Chao Li ◽  
Xian Zhong Lang
Keyword(s):  
Flow Stress ◽  
Volume Fraction ◽  
Dynamic Properties ◽  
Particle Volume Fraction ◽  
Element Model ◽  
Dynamic Mechanical Properties ◽  
Strengthening Effect ◽  
Particle Volume ◽  
The Matrix ◽  
Angular Particles

AbstractUsing image processing and recognition, a microstructure-based finite element model (FEM) was established to predict the dynamic properties of SiCp/Al composites at different strain rates ranging from 200 to 14,000 s-1. In the microstructure-based FEM, the irregular SiC particles were randomly distributed in the matrix, and its configurations did not change. The results showed that the flow stress of SiCp/Al composites with low particle volume fraction first increases and then decreases with the increasing of strain rate during the adiabatic compression. The reducing flow stress of SiCp/Al composites is caused by the inner damage and the heat softening of composites. The angular particles in SiCp/Al composites provide more strengthening effect than the circle particles when the strain is <0.62, while the circle particles provide more strengthening effect than the angular particles for strain >0.62.

scholarly journals Experimental and numerical study on surface roughness of magnetorheological elastomer for controllable friction

Friction ◽  
2019 ◽  
Vol 8 (5) ◽  
pp. 917-929 ◽  
Author(s):  
Rui Li ◽  
Xi Li ◽  
Yuanyuan Li ◽  
Ping-an Yang ◽  
Jiushan Liu
Keyword(s):  
Magnetic Field ◽  
Surface Roughness ◽  
Surface Morphology ◽  
Volume Fraction ◽  
Particle Volume Fraction ◽  
Rubber Matrix ◽  
Magnetorheological Elastomer ◽  
Particle Volume ◽  
Simulation Results ◽  
The Magnetic Field

Abstract Magnetorheological elastomer (MRE) is a type of smart material of which mechanical and electrical properties can be reversibly controlled by the magnetic field. In this study, the influence of the magnetic field on the surface roughness of MRE was studied by the microscopic modeling method, and the influence of controllable characteristics of the MRE surface on its friction properties was analyzed by the macroscopic experimental method. First, on the basis of existing studies, an improved mesoscopic model based on magnetomechanical coupling analysis was proposed. The initial surface morphology of MRE was characterized by the W-M fractal function, and the change process of the surface microstructures of MRE, induced by the magnetic interaction between particles, was studied. Then, after analyzing the simulation results, it is found that with the increase in the magnetic field and decrease in the modulus of rubber matrix, the surface of MRE changes more significantly, and the best particle volume fraction is within 7.5%–9%. Furthermore, through experimental observation, it is found that the height of the convex peak on the surface of MRE decreases significantly with the action of the magnetic field, resulting in a reduction in the surface roughness. Consistent with the simulation results, a particle volume fraction of 10% corresponds to a maximum change of 14%. Finally, the macroscopic friction experiment results show that the friction coefficients of MREs with different particle volume fractions all decrease with the decrease in surface roughness under the magnetic field. When the particle volume fraction is 10%, the friction coefficient can decrease by 24.7% under a magnetic field of 400 mT, which is consistent with the trend of surface roughness changes. This shows that the change in surface morphology with the effect of the magnetic field is an important factor in the control of MRE friction properties by magnetic field.

Tunable isolator based on magnetorheological elastomer in coupling shear–squeeze mixed mode

2018 ◽  
Vol 29 (10) ◽  
pp. 2236-2248 ◽  
Author(s):  
Dingxin Leng ◽  
Tongtong Wu ◽  
Guijie Liu ◽  
Xiaojie Wang ◽  
Lingyu Sun
Keyword(s):  
Mixed Mode ◽  
Magnetic Particle ◽  
Volume Fraction ◽  
Particle Volume Fraction ◽  
Magnetorheological Elastomer ◽  
Applied Current ◽  
Particle Volume ◽  
Vibration Mitigation ◽  
Magnetorheological Elastomers ◽  
Design Construction

In this article, the systematic design, construction, and testing of a novel tunable isolator based on magnetorheological elastomers in coupling shear–squeeze mixed mode have been studied. The influence of magnetic particle volume fraction on field-induced properties of magnetorheological elastomer isolator is studied, and the performance of vibration mitigation of magnetorheological elastomer isolator is evaluated experimentally. The results show that the frequency-shift property of magnetorheological elastomer isolator is linearly proportional to the magnetic particle volume fraction and applied current, and vibration mitigation capacity of magnetorheological elastomer isolator is remarkably enhanced by increasing the applied current. The design of magnetorheological elastomer isolator in coupling mixed mode may provide a new insight for using magnetorheological elastomers in vibration reduction applications.

Hybrid Particle/Fiber Polymer Based Composites Analysis Based on DMA Data vs. Material Property Predictions

2014 ◽  
Vol 659 ◽  
pp. 101-106
Author(s):  
Dana Motoc Luca
Keyword(s):  
Volume Fraction ◽  
Loss Modulus ◽  
Unsaturated Polyester ◽  
Particle Volume Fraction ◽  
Dynamic Mechanical Properties ◽  
Damping Factor ◽  
Hybrid Polymer ◽  
Particle Volume ◽  
Material Development ◽  
Numerical Predictions

The paper aims a comparison with respect to the dynamic mechanical properties of few hybrid polymer based composite architectures based on experimental data against micro-mechanical models based numerical predictions. The hybrid polymer based composites considered were particle-fiber combinations reinforced within an unsaturated polyester resin to provide different architectures. Variations in storage modulus (E’), loss modulus (E’’) and damping factor (tan δ) with temperature increase and different particle volume fraction were investigated. Data comparison reveals the herein composite architectures’ performances over the benchmark and enables further insight into the material development and characterization issues.

Thermal, Mechanical and Morphological Performance of BisGMA/TiO2 Nanocomposite

2007 ◽  
Vol 29-30 ◽  
pp. 241-244
Author(s):  
D. Behera ◽  
A.K. Banthia
Keyword(s):  
Dynamic Mechanical Analysis ◽  
Volume Fraction ◽  
Particle Volume Fraction ◽  
Flexural Modulus ◽  
Mechanical Analysis ◽  
Resin System ◽  
Neat Resin ◽  
Particle Volume ◽  
Entire Volume ◽  
Dynamic Mechanical

Vinyl ester BisGMA [Bisphenol-A-glycidyldimethacrylate] resin has been modified by incorporating Titanium dioxide(TiO2)nanoparticles (0.5%-2% by weight). An ultrasonic mixing process was employed to disperse the particles into the resin system prior to casting and curing test specimens. From TEM investigation, it is found that the particles are nano size (5-60nm) and dispersed throughout the entire volume of the resin. Dynamic mechanical analysis was conducted for both the neat resin and nanocomposite. In dynamic mechanical analysis, nanocomposite shows increase in storage modulus (6%), and glass transition temperature (5.8%) from neat resin system. Thermogravimetric analysis shows 7.5% better thermal stability. In addition, the nanocomposite shows enhance in the stiffness by 5% in flexural loading. The Tg and flexural modulus of the nanocomposites were enhanced as the particle volume fraction was enhanced and than decreased.

scholarly journals Performance improvement of double-tube gas cooler in CO2 refrigeration system using nanofluids

2015 ◽  
Vol 19 (1) ◽  
pp. 109-118 ◽  
Author(s):  
Jahar Sarkar
Keyword(s):  
Performance Improvement ◽  
Volume Fraction ◽  
Particle Volume Fraction ◽  
Cooling Capacity ◽  
Inlet Temperature ◽  
Refrigeration Cycle ◽  
Particle Volume ◽  
Transcritical Carbon Dioxide ◽  
The Given ◽  
Theoretical Analyses

The theoretical analyses of the double-tube gas cooler in transcritical carbon dioxide refrigeration cycle have been performed to study the performance improvement of gas cooler as well as CO2 cycle using Al2O3, TiO2, CuO and Cu nanofluids as coolants. Effects of various operating parameters (nanofluid inlet temperature and mass flow rate, CO2 pressure and particle volume fraction) are studied as well. Use of nanofluid as coolant in double-tube gas cooler of CO2 cycle improves the gas cooler effectiveness, cooling capacity and COP without penalty of pumping power. The CO2 cycle yields best performance using Al2O3-H2O as a coolant in double-tube gas cooler followed by TiO2-H2O, CuO-H2O and Cu-H2O. The maximum cooling COP improvement of transcritical CO2 cycle for Al2O3-H2O is 25.4%, whereas that for TiO2-H2O is 23.8%, for CuO-H2O is 20.2% and for Cu-H2O is 16.2% for the given ranges of study. Study shows that the nanofluid may effectively use as coolant in double-tube gas cooler to improve the performance of transcritical CO2 refrigeration cycle.

A simulation and experimental study on particle volume fraction of PMMA suspension in centrifugal fields

2021 ◽  
Author(s):  
Yosephus Ardean Kurnianto Prayitno ◽  
Tong Zhao ◽  
Yoshiyuki Iso ◽  
Masahiro Takei
Keyword(s):  
Experimental Study ◽  
Volume Fraction ◽  
Particle Volume Fraction ◽  
Particle Volume

Solidification Processing of Functionally Graded Materials by Sedimentation

1999 ◽  
Author(s):  
J. W. Gao ◽  
S. J. White ◽  
C. Y. Wang
Keyword(s):  
Functionally Graded Materials ◽  
Volume Fraction ◽  
Particle Volume Fraction ◽  
Computer Code ◽  
Functionally Graded ◽  
Particle Volume ◽  
Particle Sedimentation ◽  
Graded Materials ◽  
Free Zone ◽  
Free Region

Abstract A combined experimental and numerical investigation of the solidification process during gravity casting of functionally graded materials (FGMs) is conducted. Focus is placed on the interplay between the freezing front propagation and particle sedimentation. Experiments were performed in a rectangular ingot using pure substances as the matrix and glass beads as the particle phase. The time evolutions of local particle volume fractions were measured by bifurcated fiber optical probes working in the reflection mode. The effects of various processing parameters were explored. It is found that there exists a particle-free zone in the top portion of the solidified ingot, followed by a graded particle distribution region towards the bottom. Higher superheat results in slower solidification and hence a thicker particle-free zone and a higher particle concentration near the bottom. The higher initial particle volume fraction leads to a thinner particle-free region. Lower cooling temperatures suppress particle settling. A one-dimensional solidification model was also developed, and the model equations were solved numerically using a fixed-grid, finite-volume method. The model was then validated against the experimental results, and the validated computer code was used as a tool for efficient computational prototyping of an Al/SiC FGM.

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