The Electro-Hydraulic Control Directional Valve Based on Magneto-Rheological Fluid

2013 ◽  
Vol 567 ◽  
pp. 139-142
Author(s):  
D.D. Liu ◽  
C.R. Tang ◽  
C. Zhao
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Control Valve ◽  
Piping System ◽  
Manufacturing Cost ◽  
Hydraulic Control ◽  
Hydraulic Support ◽  
Excitation Coil ◽  
Magneto Rheological

The electro-hydraulic control directional valve based on magneto-rheological fluid using in hydraulic support is proposed. The magneto-rheological fluid represents favorable flow liquid state without external magnetic field, but it can represent mechanics quality of similarity solid in strong magnetic field. The magneto-rheological fluid may become solid within milliseconds under the action of an external magnetic field, which can realize intelligent control of hydraulic system and overcome shortcoming of traditional hydraulic valve. The electro-hydraulic control directional valve uses magneto-rheological fluid as controlling fluid, and adjusts pressure difference of action main control valve between left end and right end though changing excitation coil current of magneto-rheological valve. The electro-hydraulic control directional valve based on magneto-rheological fluid can satisfy the self-feeding hydraulic support using requirements and has low manufacturing cost. The installation and using of the electro-hydraulic control valve is more convenient and fast. It reduces the point of failure of the hydraulic supports piping system and makes hydraulic support more secure and reliable.

Study of the Performance of Practical Magneto-Rheological Elastomers

2012 ◽  
Vol 430-432 ◽  
pp. 1979-1983
Author(s):  
Wei Bang Feng ◽  
Xue Yang ◽  
Zhi Qiang Lv
Keyword(s):  
Magnetic Field ◽  
Mechanical Properties ◽  
Mechanical Property ◽  
Magnetic Properties ◽  
External Magnetic Field ◽  
Magnetic Particles ◽  
Poor Performance ◽  
Electrical And Magnetic Properties ◽  
Intelligent Material ◽  
Magneto Rheological

Magneto-rheological elastomer( MR elastomer) is an emerging intelligent material made up of macromolecule polymer and magnetic particles. While a promising wide application it has in the fields of warships vibration controlling for its controllable mechanical, electrical and magnetic properties by external magnetic field, design and application of devices based on it are facing great limitations imposed by its poor performance in mechanical properties and magneto effect. Aiming at developing a practical MR elastomer, a new confecting method was proposed in this paper. Then, following this new method and using a specificly designed solidifying matrix, an amido- polyester MR elastomer was developed with its mechanical property systemically explored.

scholarly journals Analysis of a Compact Squeeze Film Damper with Magneto Rheological Fluid

2020 ◽  
Vol 70 (2) ◽  
pp. 122-130
Author(s):  
Rahul Kumar Singh ◽  
Mayank Tiwari ◽  
Anpeksh Ambreesh Saksena ◽  
Aman Srivastava
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Squeeze Film ◽  
Vibration Level ◽  
Mr Fluid ◽  
Squeeze Film Damper ◽  
Rotor Systems ◽  
Jeffcott Rotor ◽  
Magneto Rheological ◽  
Control Feedback

Rotor systems play vital role in many modern day machinery such as turbines, pumps, aeroengines, gyroscopes, to name a few. Due to unavoidable unbalance in the rotor systems, there are lateral and torsional vibrations. Ignoring these effects may cause the system serious damages, which sometimes lead to catastrophic failures. Vibration level in rotor systems is acceptable within a range. Focus in this work is to minimize the vibration level to the acceptable range. One of the ways vibration level can be minimised is by means of providing damping. To accomplish this task in this work a new concept squeeze film damper is made by electro discharge machining which is compact in configuration, is filled with magneto-rheological (MR) fluid and tested out on one support of a Jeffcott rotor. This compact squeeze film damper (SFD) produces damping in a compact volume of the device compared to a conventional SFD. MR fluid is a smart fluid, for which apparent viscosity changes with the application of external magnetic field. This compact damper with MR fluid provides the variable damping force, controlled by an external magnetic field. In this work, proportional controller has been used for providing the control feedback. This MR damper is seen to reduce vibrations in steady state and transient input to the Jeffcott rotor. Parametric study for important design parameters has been done with the help of the simulation model. These controlled dampers can be used for reducing vibrations under different operating conditions and also crossing critical speed.

Tunable friction performance of magneto-rheological elastomer induced by external magnetic field

2017 ◽  
Vol 29 (2) ◽  
pp. 160-170 ◽  
Author(s):  
Rui Li ◽  
Dejun Ren ◽  
Xiaojie Wang ◽  
Xiang Chen ◽  
Shiwei Chen ◽  
...  
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Friction Performance ◽  
Magneto Rheological

scholarly journals Field-Induced Transversely Isotropic Shear Response of Ellipsoidal Magnetoactive Elastomers

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3958
Author(s):  
Sanket Chougale ◽  
Dirk Romeis ◽  
Marina Saphiannikova
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Shear Deformation ◽  
Transversely Isotropic ◽  
Field Direction ◽  
Mechanical Anisotropy ◽  
Cauchy Stress ◽  
Strain Behavior ◽  
Dipole Interactions ◽  
Magneto Rheological

Magnetoactive elastomers (MAEs) claim a vital place in the class of field-controllable materials due to their tunable stiffness and the ability to change their macroscopic shape in the presence of an external magnetic field. In the present work, three principal geometries of shear deformation were investigated with respect to the applied magnetic field. The physical model that considers dipole-dipole interactions between magnetized particles was used to study the stress-strain behavior of ellipsoidal MAEs. The magneto-rheological effect for different shapes of the MAE sample ranging from disc-like (highly oblate) to rod-like (highly prolate) samples was investigated along and transverse to the field direction. The rotation of the MAE during the shear deformation leads to a non-symmetric Cauchy stress tensor due to a field-induced magnetic torque. We show that the external magnetic field induces a mechanical anisotropy along the field direction by determining the distinct magneto-mechanical behavior of MAEs with respect to the orientation of the magnetic field to shear deformation.

The Variable Non-Linear Flow Channel Method and Device

2010 ◽  
Vol 136 ◽  
pp. 158-161
Author(s):  
Dan Dan Liu ◽  
Chun Rui Tang
Keyword(s):  
Space Variable ◽  
Control Valve ◽  
Channel Length ◽  
Magnetic Pressure ◽  
Flow Channel ◽  
Hydraulic Control ◽  
Linear Flow ◽  
Non Linear ◽  
Fluid Channel ◽  
Magneto Rheological

In order to overcome shortcomings of traditional hydraulic control valve, the variable non-linear flow channel method and device is proposed, which can make magneto-rheological fluid channel in the magnetic gap space variable non-linear. In the magnetic gap space setting separated magnetic pressure tablets make magneto-rheological fluid non-line fluid along the separated magnetic pressure tablets, so the magneto-rheological fluid channel length is lengthen and it can increase the utilization of a limited magnetic line. Under the condition of magnetic gap size fixedness, improving pressure difference size of controllable fluid of magnetic fluids can achieve goals of energy conservation and reducing the size of magneto-rheological valves.

scholarly journals A simulation study of excitation coil design in single-sided mpi scanner for human body application

2019 ◽  
Vol 8 (4) ◽  
Author(s):  
Nurmiza Othman ◽  
Muhamad Fikri Shahkhirin Birahim ◽  
Wan Nurshazwani Wan Zakaria ◽  
Mohd Razali Md Tomari ◽  
Md Nor Ramdon Baharom ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Physical Properties ◽  
Human Body ◽  
Simulation Study ◽  
Complex Surface ◽  
Imaging Method ◽  
Magnetic Field Generation ◽  
Excitation Coil ◽  
Particle Imaging

Magnetic particle imaging (MPI), a tomographic imaging method has been introduced for 3D imaging of human body with some potential applications such as magnetic hyperthermia and cancer imaging. It involves three important elements: tracer development using magnetic nanoparticles (MNPs), hardware realization (scanner using excitation and pickup coils), and image reconstruction optimization. Their combination will produce a high quality of image taken from any biological tissue in the human body based on the secondary magnetic field signal from the magnetized MNPs that are injected into human body. A homogeneous and adequate magnetic field strength from an excitation coil is needed to enhance the quality of the secondary signal. However, the complex surface topography of human body and physical properties of an excitation coil influence the strength and the homogeneity of the magnetic field generation at the MNPs. Therefore, this work focused on finding alternative design of excitation coil used in single sided MPI to produce up to 2 mT with high homogeneity of field distribution in the MNPs at the varied depth of 10 to 30 mm under the excitation coil. We proposed several designs with variation in physical properties and coil arrangement based on simulation study carried out by using Ansys Maxwell.

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