A Non-Linear Flow Channel Implementation Method in Magnetic Gap Space of Magneto-Rheological Valve

2010 ◽  
Vol 136 ◽  
pp. 118-121
Author(s):  
Chun Rui Tang ◽  
Dan Dan Liu
Keyword(s):  
Magnetic Field ◽  
Fluid Pressure ◽  
Flow Channel ◽  
Linear Flow ◽  
Fluid Saturation ◽  
Oil Distribution ◽  
Non Linear ◽  
Implementation Method ◽  
Magneto Rheological ◽  
The Magnetic Field

A non-linear flow channel implementation method in magnetic gap space of magneto-rheological valve is proposed in this paper. The involved magneto-rheological valve in the method has a non-line flow channel which is formed by magnetic gap space between oil inlet disc and oil distribution disc, the concentric annular trapezoidal concave of the surface of the oil inlet disc, the concentric annular trapezoidal convex of the surface of the oil distribution disc, the corresponding convex and concave trapezium between the inlet oil disc and the oil distribution disc, the surface of oil distribution disc and oil inlet disc. The method is beneficial, because the maximum magneto-rheological effect is produced by placing the magneto-rheological fluid in the magnetic field whose intensity is maximum and not more than magneto-rheological fluid saturation intensity, and the magneto-rheological fluid channel length is lengthen in the limited space of the magnetic gap, we can further poly-magnetic by using of separated magnetic sheeting under condition of taking full advantage a limited poly-magnetic cross-section of the magnetic field. The method can significantly enhance the magneto-rheological fluid pressure difference under the same magneto-rheological fluid and flow requirements, size requirements, response time requirements and energy requirements.

NONHOMOGENEOUS, NON-LINEAR DEFORMATION OF POLYMER GELS SWOLLEN WITH MAGNETO-RHEOLOGICAL SUSPENSIONS

2002 ◽  
Vol 16 (17n18) ◽  
pp. 2616-2621 ◽  
Author(s):  
DÉNES SZABÓ ◽  
MIKLÓS ZRÍNYI
Keyword(s):  
Magnetic Field ◽  
Material Properties ◽  
Strain Energy Function ◽  
Polymer Gels ◽  
Linear Elasticity Theory ◽  
Linear Deformation ◽  
Linear Character ◽  
Non Linear ◽  
Magneto Rheological ◽  
The Magnetic Field

Polymer gels swollen with a magneto-rheological suspension are highly elastic materials with considerable magnetic susceptibility. In this work the magnetic field induced deformation and motion of these magnetic polymer systems is discussed. We present a continuum material model by introducing magnetic equations into non-linear elasticity theory. The material properties of these magnetic rubber-like substances are characterized with a Langevin type magnetization and a neo-Hookean strain energy function. The non-linear character of the equations that describe the material properties and the nonhomogeneity of the deformation lead to a unique deformation mechanism. In order to demonstrate the characteristics of the magnetic field induced deformations we present numerical and finite element calculations and compare them with experimental results.

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.

In Search of the Jerk Element

2021 ◽  
Author(s):  
Zachary P. Belyaev ◽  
Samuel N. Downes ◽  
Philip A. Voglewede
Keyword(s):  
Magnetic Field ◽  
Motion Planning ◽  
System Performance ◽  
Theoretical Background ◽  
Physical Parameters ◽  
Common Elements ◽  
Planning And Control ◽  
Magneto Rheological ◽  
And Control ◽  
The Magnetic Field

Abstract Mechanical components, such as springs, dampers and mass, alter and influence an engineered system’s motion based upon a system’s position, velocity and acceleration, respectively. This paper aims to discover and develop another element (dubbed the damper) which provides a force proportional to a system’s jerk (i.e., the derivative of acceleration) to better engineer a system’s response. By utilizing the known applications of jerk in motion planning and control theory, existing possible physical implementations and uses of jerk and the jerk element are discussed in relation to its influence on the system’s response, specifically vibration. Using a Buckingham Pi approach, the theoretical background of the jerk element is presented and possible physical parameters are combined to show how the jerk element could be created from common elements and parameters. The most promising approach of varying the magnetic field of existing magneto-rheological dampers is developed to give an example of the jerk element along with the difficulties and concerns in developing the jerk element. This paper serves less of a purpose towards answering all questions of the jerk element, but rather focuses more on posing the appropriate questions which sets the stage for an easily realizable future jerk element which can improve system performance.

Characteristics of Magneto-Rheological Elastomer under Stick-Slip Condition

2020 ◽  
Vol 842 ◽  
pp. 193-198
Author(s):  
Kwang Hee Lee ◽  
Chul Hee Lee
Keyword(s):  
Magnetic Field ◽  
Glass Plate ◽  
Static Friction ◽  
Low Noise ◽  
Friction Behavior ◽  
Stick Slip ◽  
The Difference ◽  
Magneto Rheological ◽  
Squeal Noise ◽  
The Magnetic Field

This paper examines the characteristics of stick-slip phenomena between the glass plate and Magneto-Rheological Elastomer (MRE) surface. Stick-slip phenomena are the spontaneous jerking motion that occurs while two objects are sliding over each other, usually accompanied by noise. Stick-slip is generated when it involves discontinuous frictional degradation when moving from static friction to dynamic friction. The phenomena can lead to uneven wear patterns, vibration and squeal noise which cause a shorter lifespan for the corresponding mechanical elements. MREs are kind of function materials to consist of a polymeric matrix with embedded ferromagnetic particles. Mechanical properties of the MREs can be controlled by the application of magnetic fields. The magnetic field-based controllability can be applied to the control of stick-slip phenomena. The friction experiment is conducted with the Reciprocating Friction Tester (RFT). The sliding speed of the RFT should be in low-speed conditions in order to make the stick-slips relatively easy to occur. A uniform magnetic field and a weight load are applied to the MRE sample to observe the effect of various experimental parameters on the movement of the stick-slip. In addition, frictional sounds due to the stick-slip phenomenon under different loads and magnetic field strength are measured and analyzed. The results of this experiment show that as the strength of the magnetic field increases, the difference in stiffness between the wipers-glass decreases, mitigating fricatives. The result is expected to be well applied to low-noise automotive wipers based on the controllability of friction behavior and squeal noise.

The Effect of Particle Concentration and Magnetic Field on Tribological Behavior of Magneto-Rheological Fluid

2011 ◽  
Vol 314-316 ◽  
pp. 58-61 ◽  
Author(s):  
Wan Li Song ◽  
Chul Hee Lee ◽  
Seung Bok Choi ◽  
Myeong Woo Cho
Keyword(s):  
Magnetic Field ◽  
Friction Coefficient ◽  
Wear Mechanism ◽  
Particle Concentration ◽  
Tribological Behavior ◽  
Wear Loss ◽  
Wear Properties ◽  
Mr Fluid ◽  
Magneto Rheological ◽  
The Magnetic Field

In this paper, the effect of particle concentration and magnetic field on the tribological behavior of magneto-rheological (MR) fluid is investigated using a pin-on-disc tribometer. The wear loss and friction coefficient are measured to study the friction and wear properties of MR fluid. The morphology of the worn pin is also observed by scanning electron microscope (SEM) in order to analyze the wear mechanism. The results obtained in this work show that the wear loss and friction coefficient decrease with increasing particle concentration under the magnetic field. Furthermore, it is demonstrated that the magnetic field has a significant effect on improving tribological properties of MR fluid, especially the one with high particle concentration. The predominant wear mechanism of the MR fluid has been identified as abrasive wear.

The Research of Capacitance Characteristics of MRF

2012 ◽  
Vol 246-247 ◽  
pp. 1096-1101
Author(s):  
Song Wang ◽  
Guo Tian He ◽  
Li Song ◽  
Ze Yu Xu ◽  
Ying Chun Ran
Keyword(s):  
Magnetic Field ◽  
Dielectric Constant ◽  
Electrical Characteristics ◽  
Field Change ◽  
Aircraft Manufacturing ◽  
Magnetic Field Change ◽  
Capacitance Characteristics ◽  
Magneto Rheological ◽  
Magnetic Induction Intensity ◽  
The Magnetic Field

With the development of theory that research on Magneto-Rheological Fluids (MRF), the MRF have been used in many fields in our life. The electrical characteristics of MRF can be widely used in automatic control, medical, automotive, aircraft manufacturing and many other areas .Firstly, this article have derived the formula of MRF between capacitance and Dielectric constant, made the Capacitors which can load the MRF. And then we measure the change of capacitance which is filled with the MRF when the time of magnetic field change, And we also measure the sensitivity of the dielectric constant of different concentrations of MRF as the magnetic field changes. And at last, we have made the curve of the capacitance - magnetic induction intensity the experimental results have been analyzed. We have the conclusion that when the magnetic field increases, the dielectric constant is also increases, resulting in increased capacitance of the conclusions of MRF. Introduction

An Experimental Analysis of Vibration Induced Behaviour in Magnetorheological Fluids

2017 ◽  
Author(s):  
Paul-Alexis Novikoff ◽  
Laurent Eck ◽  
Moustapha Hafez
Keyword(s):  
Magnetic Field ◽  
Rotation Axis ◽  
Cylinder Surface ◽  
Stress Variation ◽  
Particle Chain ◽  
Free Air ◽  
Magneto Rheological ◽  
Magnetic Poles ◽  
The Magnetic Field ◽  
Viscosity Dependence

Magneto-rheological fluids (MRF) are commonly applied in MRF brakes and vibration damping. The apparent viscosity dependence with respect to the magnetic field has been addressed in detail in the state of the art. The aim of this paper is to experimentally study the vibration effects on the particle chain-like structures and, as a consequence, the shear stress variation applied to the fluid. Three vibration configurations have been applied to a ferromagnetic cylinder rotating between two magnetic poles filled with MRF a “Z-vibration” where the generated displacement is along the rotation axis of the shearing cylinder, a “θ-vibration”, tangential to the cylinder, and an “R-vibration”, normal to the cylinder surface. First we focus on the vibration mode characterisation in free air, and then when plunged in the fluid. In a second step, we measure the reactive torque generated on the clutch under different magnetic field intensities with different rotation speeds and vibration amplitudes. It appears that the “R-vibration” configuration is providing the most influence, up to 20% of torque reduction observed at moderate B field. The “Z-vibration” and the “θ-vibration” configurations respectively have less influence on the torque, nevertheless vibrations always tend to decrease the corresponding yield stress in the MRF.

Comparison of Affecting Factors on the Shear Stress Output of Cylinder-Typed MRF Clutch

2015 ◽  
Vol 1094 ◽  
pp. 453-457
Author(s):  
Hai Feng Ji ◽  
Chun Fu Gao ◽  
Xin Sheng He ◽  
Guang Zhang
Keyword(s):  
Magnetic Field ◽  
Shear Stress ◽  
Affecting Factors ◽  
Bingham Model ◽  
Theoretical Derivation ◽  
Proportionality Constant ◽  
Magneto Rheological ◽  
The Relationship ◽  
The Magnetic Field ◽  
Main Influence

With the purpose of studying the main influence on the cylinder-typed magneto-rheological fluid (MRF) clutch, the relationship between the output of shear stress and its affecting factors is presented in this paper; through theoretical derivation from the Bingham Model and the cylinder-typed shear model, the stress born by the MRF in the clutch is analysed, and the affecting factors on the clutch is also simulated and verified through experiments. The study shows that as the magnetic field strengthens, the shear stress of the cylinder-typed MRF clutch grows linearly, with proportionality constant at 0.162; the increase of shear rate, relevant to the magnetic field strength, makes little difference to the torque output, with proportionality constant at 0.00026B. The results indicate that mechanical-electrical integration of clutch devices can be achieved through the control of magnetic field output of the electromagnet.

Developing of the Experimental Device that Test Magneto Rheological Fluid(MRF) Shear Yield Stress Nnder Non Uniform Composite Field

2015 ◽  
Vol 667 ◽  
pp. 385-390
Author(s):  
Wei Zeng Chen ◽  
Guang Zhang ◽  
Xin Sheng He ◽  
Shao Qing Ren ◽  
Peng Huang
Keyword(s):  
Magnetic Field ◽  
Yield Stress ◽  
Experimental Device ◽  
Actual Condition ◽  
Shear Yield Stress ◽  
Fluid Shear ◽  
Composite Field ◽  
Shear Yield ◽  
Magneto Rheological ◽  
The Magnetic Field

In order to study magneto rheological fluid shear characteristics developing of magnetic field and temperature field under the actual condition (non-uniform composite field), Experimental device that test magneto rheological fluid (MRF) Shear yield stress under Non uniform composite field was developed. The device of the magnetic field distribution, temperature conductivity, shear yield stress are studied in theory and prototype production, and then testing the Shear yield stress of magneto rheological fluids of different magnetic field, temperature yield . The adjusting range of temperature of the experimental device is for 0-200, the magnetic field adjusting range by adjusting the current of the electromagnetic coil in the 0mt-300mt. Makes the air gap magnetic field intensity is 20mt, magneto rheological fluid in the shear rate at , the research of magneto rheological fluid shear yield stress with the magnetic field variation different temperatures (T=10, T=50, T=100,T=130, T=150, T=170) . The experimental results show that: in the 10-170, the temperature value basically does not affect the shear yield stress of the MR fluid, but the temperature is less than 10 and the temperature is greater than 170, the effects that temperature size on MRF Shear yield stress is relatively large.

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