The study on the mechanical properties of magnetorheological elastomers under triaxial compression

2020 ◽  
pp. 1045389X2097827
Author(s):  
Yong Xu ◽  
Ming Li ◽  
Hao Li ◽  
Shihong Zhang ◽  
Hui Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Magnetic Flux ◽  
Magnetic Particles ◽  
Poisson Ratio ◽  
Triaxial Compression ◽  
Compression Modulus ◽  
Magnetic Flux Density ◽  
Stress Strain ◽  
Magnetorheological Elastomers ◽  
Volume Compression

In order to design magnetorheological elastomers (MREs) based craftsmanship for metal forming, a comprehensive study on the mechanical properties of MREs under triaxial compression is required. An experimental setup integrating free compression and triaxial compression is designed to characterize isotropic MREs specimens under compression mode. The results showed that the MREs specimen in mold had successively experienced free compression stage, transition stage and triaxial compression stage during the experiment. The stress-strain curves of the MREs specimen changed when the concentration of magnetic particles increased from 0 to 44.7%, and the strain required to reach the transition stage was reduced. The effect of magnetic flux density on the stress-strain curves of the MREs specimen depended on the concentration of magnetic particles. The measured data obtained at different strain rates revealed maximum changes of 15.7% and 0.096% in volume compression modulus and Poisson ratio, respectively, which occurred under the magnetic flux density of 200 mT and CIP concentrations of [Formula: see text]. In this study, through a set of experiments, the stress-strain curves of the MREs specimen under different concentrations was elucidated, and their effects on the volume compression modulus and Poisson ratio were discussed.

Transport of Magnetic Particles Under a Uniform Magnetic Field in Microchannels

2013 ◽  
Author(s):  
Gui-Ping Zhu ◽  
Nam-Trung Nguyen
Keyword(s):  
Magnetic Field ◽  
Field Strength ◽  
Magnetic Flux ◽  
Flux Density ◽  
Uniform Magnetic Field ◽  
Magnetic Particles ◽  
Independent Solution ◽  
Magnetic Flux Density ◽  
Mixing Efficiency ◽  
Water Mixture

This paper reports the numerical and experimental investigation on magnetic particle concentration in a uniform magnetic field. The flow system consists of water-based ferrofluid and glycerol/DI water mixture streams. Two regimes were observed with spreading and mixing phenomena. With a low magnetic field strength, the spread of magnetic particles is caused by improved diffusion migration. With a relatively high field strength, instability at the interface would occur due to the mismatch in magnetization of the fluid streams. The transport of magnetic particles is induced by chaotic mixing of the fluids caused by a secondary flow. The mixing phenomena are characterized by magnetic flux density. For configuration with flow rate and viscosity ratio (between diamagnetic and magnetic streams) being set at 1 and 0.5, the mixing efficiency analyzed based on magnetic particles concentration increases approximately by 0.3 at around 3.5 mT. This value of magnetic flux density indicates the requirement on instability inception. The mixing efficiency increases with magnetic flux density increases further. Complete mixing can be achieved with a magnetic flux density at around 10 mT. The magnetic approach offers a wireless, heat-free and pH-independent solution for a lab-on-a-chip system.

Effect of Porosity on Mechanical Properties of Rubber

1995 ◽  
Vol 68 (2) ◽  
pp. 219-229 ◽  
Author(s):  
A. I. Kasner ◽  
E. A. Meinecke
Keyword(s):  
Experimental Data ◽  
Mechanical Properties ◽  
Shape Factor ◽  
Compression Modulus ◽  
Stress Strain ◽  
Shape Factors ◽  
Porosity Level ◽  
Apparent Modulus ◽  
Analytical Expressions ◽  
Cylindrical Samples

Abstract Cylindrical samples, with different shape factors and levels of porosity, were prepared from a model EPDM compound and tested in compression. The modulus was reduced considerably with the introduction of porosity, especially when the shape factor was high. The stress-strain curves showed nonlinearity which depends on the shape factor and porosity level, and is related to bubble closure. The apparent modulus of bonded blocks was found to consist of two components: homogeneous compression modulus and a hydrostatic contribution. The first was obtained by compression of blocks between lubricated compression plates. It can be predicted from analytical expressions adapted from composite theories for high density foams in tension. The second arises from the pressure buildup inside the bonded blocks and depends on the shape factor and the porosity level. These moduli, after correcting for compressibility, were used to develop approximate relations describing the stress-strain curves of porous bonded blocks. The stress-strain curves of samples with different shape factors and levels of porosity could be predicted from experimental data or FEA estimates.

scholarly journals Experimental Research on the Mechanical Properties of Heated Granite after Rapid Cooling

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Huifen Han ◽  
Junliang Peng ◽  
Yintong Guo ◽  
Qiuyun He ◽  
Jun Zhou ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Wave Velocity ◽  
Cold Water ◽  
Triaxial Compression ◽  
P Wave ◽  
Reservoir Rock ◽  
Stress Strain ◽  
Rapid Cooling ◽  
Wave Velocities ◽  
Rock Structure

Understanding the mechanical properties of the reservoir rock under different temperatures after rapid thermal cooling is necessary for safe and effective deep geoengineering applications, including deep mining projects, deep geological disposal of nuclear waste, and geothermal energy extraction. This paper is devoted to investigating the effect of rapid cooling on the mechanical behavior of the granite rock. At first, high-temperature heating was conducted. The 24 samples were divided into six groups and were heated at 100, 200, 300, 400, 500, and 600°C, and once they had reached the chosen temperature, they were immediately cooled with a cold water container, and the temperature of water in the pan was 25°C. After the thermal treatment, the samples were measured using ultrasonic wave velocities, and then they were deformed under uniaxial and triaxial compression tests. The P -wave velocity, damage characteristics, stress-strain curves, compressive strength, and Young’s modulus of the samples were presented considering different thermal temperatures. The results confirmed that the P -wave velocities of the samples generally decrease with temperature. P-wave velocity can indirectly reflect the damage of the rock structure. These changes represent a negative exponential relationship between P -wave velocity and hold temperature following cooling. As the samples experienced greater temperatures, the peak strength and elastic characteristics also significantly reduced. This is mainly due to thermally induced damage in the form of both intergranular and intragranular cracks. The stress-strain response revealed that the failure mode can change from brittle to quasi-brittle fracturing following treatment at increasingly greater temperatures.

Simulation and Validation of an Anisotropic Magnetorheological Elastomers Mold with Various Alignment Angles

2018 ◽  
Vol 772 ◽  
pp. 66-70
Author(s):  
Ilham Bagus Wiranto ◽  
Ubaidillah ◽  
Dody Ariawan ◽  
Faishal Harish ◽  
Saiful Amri Mazlan ◽  
...  
Keyword(s):  
Magnetic Flux ◽  
Flux Density ◽  
Magnetic Flux Density ◽  
Mold Design ◽  
Magnetorheological Elastomers ◽  
Density Prediction ◽  
Best Value ◽  
The Matrix ◽  
Particle Alignment ◽  
The Difference

In this study, anisotropic magnetorheological elastomers (MREs) mold design with capability of aligning the filler in several angles (0 ̊, 45 ̊, and 90 ̊) were developed. The mold was equipped with electromagnet coil to generate the magnetic flux. The distribution of magnetic flux density in the mold and inside the chamber was investigated by using finite element magnetic analysis. Magnetic flux density of 0.3 T was considered best value to form good particle alignment in the matrix. Moreover, the mold design was fabricated using same material as in the simulation. The magnetic flux density was taken at casing wall and measured by gauss-meter. The data was compared with simulation results. The differences between experimental and simulation is in the range of 6-40 mT. Since the difference is insignificant, it can be said that the data is valid. Finally, the model can be used for further magnetic flux density prediction inside the chamber. In the simulation, it was found that the current needed to generate at least 0.3 T inside the chamber for 0 ̊, 45 ̊, and 90 ̊ are 0.2A, 0.1A, and 3A, respectively.

Experimental Research on Deformation Properties of Gangue-Paste Filling Material in Mine

2013 ◽  
Vol 734-737 ◽  
pp. 746-750
Author(s):  
Jun Wei Shi
Keyword(s):  
Mechanical Properties ◽  
Uniaxial Compression ◽  
Triaxial Compression ◽  
Strain Curve ◽  
Filling Material ◽  
Stress Strain Curve ◽  
Stress Strain ◽  
Deformation Stage ◽  
Plastic Hardening ◽  
Softening Stage

According to the mechanical properties of paste filling body under special environment such as high temperature high humidity high stress and high airtight) in gob, mechanical properties of gangue-paste filling body was studied with the method of field core and laboratory test. The complete stress-strain curve of filling body under the condition of uniaxial and triaxial and the ultimate compressive strength under different confining pressure station were obtained through uniaxial and triaxial compression test. Six stages of uniaxial compression complete stress-strain curve (compression stage, elastic deformation stage, non-stable developing stages, plastic hardening stage, stress softening stage and residual deformation stage) were improved and developed. The deformation characteristics of filling body under triaxial compression were different from that under uniaxial compression. Namely the deformation of filling body under triaxial compression only appeared two deformation stages: linear deformation stage and plastic hardening stage, but had no softening stage basically under different confining pressures, which was benefit for controlling the ground subsidence and preventing the ground buildings.

Research on Distribution of Magnetic Particles Based on Magnetic Field Control Grinding Wheel

2013 ◽  
Vol 797 ◽  
pp. 428-431
Author(s):  
Shao Hui Yin ◽  
Sheng Gong ◽  
Feng Jun Chen ◽  
Ming Wang
Keyword(s):  
Magnetic Field ◽  
Surface Roughness ◽  
Magnetic Flux ◽  
Magnetic Particles ◽  
Magnetic Particle ◽  
Particle Distribution ◽  
Magnetic Flux Density ◽  
Grinding Wheel ◽  
Field Control ◽  
Orderly Arrangement

In order to solve the problem of the randomly arrangement of the diamond abrasives, a novel orderly arrangement grinding wheel was developed, which used magnetic field to control the magnetic particles to drive diamond abrasives orderly arrangement. Effects of magnetic flux density on magnetic particle distribution was studied. And effects of magnetic particle proportion on magnetic particle distribution was studied. Grinding experiments were carried out on the tungsten carbide YG8 and surface roughness after grinding was also analyzed.

scholarly journals Villari Effect at Low Strain in Magnetoactive Materials

Materials ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2472 ◽  
Author(s):  
Graciela Riesgo ◽  
Laura Elbaile ◽  
Javier Carrizo ◽  
Rosario Díaz Crespo ◽  
María Ángeles García ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Magnetic Flux ◽  
Cross Section ◽  
Magnetic Particles ◽  
Magnetic State ◽  
Soft Magnetic ◽  
Magnetic Composites ◽  
The Cross ◽  
Silicone Matrix ◽  
Villari Effect

Magnetic composites of soft magnetic FeGa particles embedded in a silicone matrix have been synthesized. The Villari effect has been studied depending on the size and concentration of the particles and on the magnetic state of the composite. The results indicate a decrease in the Villari effect when the concentration of the magnetic particles increases. These results suggest a relationship between the Villari effect and the mechanical properties of the composites. The Young’s modulus of the composites has been obtained by microindentation and their values related to the intensity and slope of the Villari signals. The results are explained on the basis that the reduction in the cross section of the composite when submitted to stress is the main origin of the variation of the magnetic flux in the Villari effect in this kind of composite. It has also been obtained that the magnetic state of the composite plays an important role in the Villari signal. When the magnetization of the composite is greater, the magnetic flux across the composite is greater too and, so, the same reduction in the cross section originates a greater Villari signal.

The Effect of Magnetic Field on Magnetorheological Composites - Artificial Neural Network Based Modelling and Experiments

2015 ◽  
Vol 816 ◽  
pp. 327-336 ◽  
Author(s):  
Mateusz Kukla ◽  
Paweł Tarkowski ◽  
Jan Górecki ◽  
Ireneusz Malujda ◽  
Krzysztof Talaśka
Keyword(s):  
Neural Network ◽  
Magnetic Field ◽  
Mechanical Properties ◽  
Magnetic Flux ◽  
Design Parameters ◽  
Compression Tests ◽  
Static Compression ◽  
Magnetorheological Elastomers ◽  
Magnetic Strength ◽  
Set Up

Looking for new applications of the available materials, such as magnetorheological elastomers (MERs) is an important element of machine design process. To this end it is necessary to determine their fundamental mechanical properties, including Young’s modulus and shear modulus. These properties are determined experimentally by testing the material in compression, tension and shear. In the case of the analysed group of materials the above-mentioned constants depend, inter alia, on the parameters of magnetic field acting on them. Therefore, it is necessary to determine the character and the extent of variation of the mechanical properties as a function of the physical constants characterising the active magnetic field, namely magnetic flux and magnetic intensity (field strength).This paper presents the results of static compression tests carried out on magnetorheological elastomers. The parameters measured during the static compression test were force and displacement at a pre-set magnetic flux. The maximum strength of the induced magnetic field was limited by the design parameters of the test set-up. In order to determine the behaviour of the material at greater values of magnetic strength and flux the properties of a real material were modelled with a neural network. The simulation was carried out using a simple, one-layer neural network. The chosen network training approach was error backpropagation. This approach enables approximation and predicting of changes of the properties of the tested material. The output results will enable deriving an analytical model of the tested MREs.

Characterization and modeling of hard magnetic particle–based magnetorheological elastomers

2020 ◽  
pp. 1045389X2094256
Author(s):  
Nader Mohseni Ardehali ◽  
Masoud Hemmatian ◽  
Ramin Sedaghati
Keyword(s):  
Magnetic Field ◽  
Magnetic Flux ◽  
Flux Density ◽  
Magnetic Particle ◽  
Excitation Frequency ◽  
Viscoelastic Behavior ◽  
Magnetic Flux Density ◽  
Driving Frequency ◽  
Magnetorheological Elastomers ◽  
Magnetic Poles

Hard magnetic particle–based magnetorheological elastomers are novel magnetoactive materials in which, unlike the soft particle–based magnetorheological elastomers, the particles provide magnetic poles inside the elastomeric medium. Therefore, the stiffness of the hard magnetic particle–based magnetorheological elastomers can be increased or decreased by applying the magnetic field in the same or opposite direction as the magnetic poles, respectively. In the present work, the viscoelastic properties of hard magnetic particle–based magnetorheological elastomers operating in shear mode have been experimentally characterized. For this purpose, hard magnetic particle–based magnetorheological elastomers with 15% volume fraction of NdFeB magnetic particles have been fabricated and then tested under oscillatory shear motion advanced rotational magneto-rheometer to investigate their viscoelastic behavior under varying excitation frequency and magnetic flux density. The influence of the shear strain amplitude and driving frequency is examined under various levels of applied magnetic field ranging from −0.2 to 1.0 T. Finally, a field-dependent phenomenological model has been proposed to predict the variation of storage and loss moduli of hard magnetic particle–based magnetorheological elastomers under varying excitation frequency and applied magnetic flux density. The results show that the proposed model can accurately predict the viscoelastic behavior of hard magnetic particle–based magnetorheological elastomers under various working conditions.

Static and Dynamic Characterization of Magnetorheological Elastomers Under Shear Mode Operation

2018 ◽  
Author(s):  
Ashkan Dargahi ◽  
Ramin Sedaghati ◽  
Subhash Rakheja
Keyword(s):  
Magnetic Flux ◽  
Shear Strain ◽  
Flux Density ◽  
Volume Fraction ◽  
Dynamic Properties ◽  
Magnetic Flux Density ◽  
Shear Mode ◽  
Iron Particles ◽  
Magnetorheological Elastomers ◽  
Mode Operation

Static and dynamic properties of six magnetorheological elastomers (MRE) with iron particles volume fraction ranging from 12.5% to 40% were experimentally characterized under shear mode operation. The experiments were designed on the basis of standardized methods defined in ISO-1827 and ISO-4664. The static shear stress-shear strain data obtained under strains up to 30% were used to quantify absolute and relative MR effects of the MREs as functions of magnetic flux density in the 0 to 450 mT range. The MRE specimen with highest iron particles fraction and a softening agent revealed greatest MR effect. The dynamic characteristics of this MRE specimen were then evaluated under harmonic excitations in the 0.1–50 Hz frequency range with shear strain amplitude and magnetic flux density ranging from 2.5 to 20%, and 0 to 450 mT, respectively. The data were then utilized to evaluate elastic and loss shear moduli of the specimen.

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