Development of Large Capacity Semi-Active Seismic Damper Using Magneto-Rheological Fluid

2004 ◽  
Vol 126 (1) ◽  
pp. 105-109 ◽  
Author(s):  
Hiroshi Sodeyama ◽  
Kohei Suzuki ◽  
Katsuaki Sunakoda
Keyword(s):  
Magnetic Fields ◽  
Large Scale ◽  
Hysteresis Loops ◽  
Mr Damper ◽  
Damping Force ◽  
Engineering Structures ◽  
Mr Fluid ◽  
Large Capacity ◽  
Mr Fluids ◽  
Magneto Rheological

In recent years, there has been increasing research in several industrial fields for development of semi-active vibration control devices. In particular, devices using magneto-rheological (MR) fluid have been attracting great research interest because they can realize high performance as capacity-variable dampers. MR fluids are controllable fluids that respond to applied magnetic fields. Applied magnetic fields drastically change the viscosity of MR fluids from an oily state to a semi-solid state. This paper describes a study on a large capacity device using an MR fluid, i.e., an MR damper. This developed MR damper provides a maximum damping force of 300 kN. Various tests were carried out and the dynamic characteristics, force-displacement hysteresis loops and controllable forces were investigated. These tests verified that the MR damper provides a technology that enables effective semi-active control of large-scale structure systems, i.e., real buildings and civil engineering structures.

Magneto-Rheological (MR) Damper Design for High-Flowrate Suspensions

2013 ◽  
Author(s):  
Riaan F. Meeser ◽  
P. Schalk Els ◽  
Sudhir Kaul
Keyword(s):  
Mr Damper ◽  
Damping Force ◽  
Mr Fluid ◽  
Bingham Plastic ◽  
Damping Characteristics ◽  
Final Design ◽  
Variable Damping ◽  
Input Variables ◽  
Damper Design ◽  
Magneto Rheological

This paper presents the design of a magneto-rheological (MR) damper for an off-road vehicle where large suspension travel and high flow rates, as compared to typical passenger car suspensions, are required. The MR damper is expected to enhance the capability of the suspension system by allowing variable damping due to inherent properties of the MR fluid. MR fluids exhibit a reversible behavior that can be controlled with the intensity of a magnetic field, allowing a change in the effective viscosity and thereby in the damping characteristics of the fluid. A mathematical model of the proposed damper has been developed using the Bingham plastic model so as to determine the necessary geometry for the damper designed in this study, using the fluid flow rate and current to the electromagnet as the input variables. The model is used to compute the damping force, and the analytical results show that the designed MR damper provides the required range of damping force for the specific vehicle setup that is being used for this study. A valve-mode MR fluid channel has been designed such that the required minimum damping is reached in the off-state, and the desired maximum damping is reached in the on-state. For manufacturing and size considerations, the final design incorporates a triple pass layout with the MR fluid flowing through the three passages that are arranged in an S-shape so as to minimize the cross section of the electromagnet core.

Study on Design Method of Magneto-Rheological Fluid Shock Absorber Employing Shear Rate Profiles and Experimental Tests

2011 ◽  
Vol 121-126 ◽  
pp. 1095-1099
Author(s):  
Chang Rong Liao ◽  
J.H. Hao ◽  
D.X. Zhao ◽  
K.L. Wang
Keyword(s):  
Differential Equation ◽  
Shear Stress ◽  
Analytical Study ◽  
Shock Absorber ◽  
Damping Force ◽  
Mr Fluid ◽  
Annular Channels ◽  
Mr Fluids ◽  
Stress Profiles ◽  
Magneto Rheological

The flow differential equation for Magneto-rheological (MR) fluids in annular channels of MR fluid shock absorber is set up and several rational simplifications are made. Analytical shear stress profiles of MR fluids through annular channels are obtained via solution of the flow differential equation. An analytical study on MR fluid shock absorber is present employing shear stress profiles. Both boundary conditions and compatible conditions are established. Both flow velocity profiles and total volumetric flow rate are developed by integration by parts and numerical integration. The prediction method for damping force of MR fluid shock absorber is developed via simultaneous equations. The analytical study on MR fluid shock absorber is validated by means of reformative Herschel–Bulkley constitutive model, in which flow velocity profiles and flow regions boundary radii are drawed. A MR fluid shock absorber, which is designed and fabricated in Chongqing University, is tested by electro-hydraulic servo vibrator in National Center for Test and Supervision of Coach Quality. The experimental results reveal that the methodology is able to predict damping force of MR fluid shock absorber via shear rate profiles and experimental damping forces are in good agreement with analytical those.

Design and Development of Magneto Rheological Dampers for Bicycle Suspensions

1999 ◽  
Author(s):  
Mehdi Ahmadian
Keyword(s):  
Dynamic Performance ◽  
Mr Damper ◽  
Test Results ◽  
Design And Development ◽  
Damping Force ◽  
Mr Fluid ◽  
Performance Improvements ◽  
Mr Dampers ◽  
Force Velocity ◽  
Magneto Rheological

Abstract The design and fabrication of a magneto rheological (MR) damper for bicycle suspension applications is addressed. Two 1998 Judy® Dampers are retrofitted with MR valves, to achieve the damping force adjustability that the MR fluid offers. One design attempts to use as many of the Judy® Damper components as possible. The second design significantly modifies the Judy® Damper, to better accommodate the MR valve and ease of fabrication and assembly, although fitting into the same envelope as the Judy® damper for a direct retrofit. The two MR dampers are fabricated and assembled for force-velocity characterization testing. The test results show that properly-designed MR dampers can provide significant dynamic performance improvements, as compared to conventional passive bicycle dampers.

Design and Performance Analysis on MR-Shock Absorber

2014 ◽  
Vol 984-985 ◽  
pp. 648-655
Author(s):  
M.L. Brabin Nivas ◽  
T. Prabaharan ◽  
J. Libin ◽  
T. Bibin Jose
Keyword(s):  
Magnetic Field ◽  
Mr Damper ◽  
Fast Response ◽  
Damping Force ◽  
Clear Fluid ◽  
Carrier Fluid ◽  
Fluid Turbulence ◽  
Mr Fluids ◽  
And Performance ◽  
Magneto Rheological

Abst r a c t -Magneto rheological aqueous is an old advancing to the bazaar at top speed. Excellent appearance like fast response, simple interface amid electrical ability ascribe and automated ability output, and absolute controllability accomplish MRF technology adorable for abounding applications.The aim of this project is preparation of MR-fluids by using the different types of carrier fluid mixed with iron powder and stability and magnetic properties are analysed. Thesedimentation of iron particles can be reduced by using additives. The sedimentation can be analysed by boundary variation of the clear fluid to the fluid turbulence. The viscosity of smart fluid can be increased by varying the applied magnetic field.The performance of the MR-damper depends on the applied maximum magnetic field and the hydraulic circuit design. The MR-damper force by increasing the magnetic field can be analysed by sing the FEMM V4 Software.Damping force depends on the excitation of current and magnetic field.Key words: Rheological, magnetic field, damping force, FEMM, flux density

Optimal Design of Magneto-Rhological Damper

2012 ◽  
Vol 220-223 ◽  
pp. 1865-1870
Author(s):  
Wei Wang ◽  
Pin Qi Xia
Keyword(s):  
Optimal Design ◽  
Dynamic Range ◽  
Mr Damper ◽  
Nonlinear Property ◽  
Structure Parameter ◽  
Damping Force ◽  
Mr Fluid ◽  
Maximal Output ◽  
Three Stages ◽  
Magneto Rheological

For the complex nonlinear property and a lot of regulatory parameter, it is difficult to design a reasonable magneto-rheological (MR) damper by simply process or experience. To solve this problem a structural optimization has been presented in this article. Three stages have been discussed in the article. By calculate the flux of MR fluid based on the yield stress of MR fluid, selected common design targets such as maximal output damping force, dynamic range and consult volume of damper has been presented in formula respectively with the parameter according to damper structure. By approximate the magnetic circle, the power of excitation also has been presented as an expression of structure parameter. An optimum method named multi-goal attach has been applied to solve the optimum problem. Finally some confirmation and experiment results have been presented. The experiment results indicated that the method presented in the article was effectively.

Damping characteristics of a magneto-rheological damper with dual independent controllable ducts

2021 ◽  
pp. 1045389X2110188
Author(s):  
Jianqiang Yu ◽  
Xiaomin Dong ◽  
Tao Wang ◽  
Zhengmu Zhou ◽  
Yaqin Zhou
Keyword(s):  
Dynamic Range ◽  
Fluid Flows ◽  
Mr Damper ◽  
Viscous Damping ◽  
The Novel ◽  
The Finite Element Method ◽  
Damping Force ◽  
Damping Characteristics ◽  
Magneto Rheological ◽  
The Mathematical Model

This paper presents the damping characteristics of a linear magneto-rheological (MR) damper with dual controllable ducts based on numerical and experimental analysis. The novel MR damper consisting of a dual-rod cylinder system and a MR valve is used to reduce the influences of viscous damping force and improve dynamic range. Driven by the dual-rod cylinder system, MR fluid flows in the MR valve. The pressure drop of the MR valve with dual independent controllable ducts can be controlled by tuning the current of two independent coils. Based on the mathematical model and the finite element method, the damping characteristics of the MR damper is simulated. A prototype is designed and tested on MTS machine to evaluate its damping characteristics. The results show that the working states and damping force of the MR damper can be controlled by the two independent coils.

Effect of Centrifugal Force Effect on Magneto-Rheological Fluid Clutches

2002 ◽  
Author(s):  
Vijay A. Neelakantan ◽  
Gregory N. Washington
Keyword(s):  
Magnetic Fields ◽  
Design Methodology ◽  
Volume Fraction ◽  
The Other ◽  
Particle Orientation ◽  
Centrifugal Forces ◽  
Mr Fluid ◽  
Set Up ◽  
Magneto Rheological ◽  
Very High

The property of magnetorheological fluids to change their yield stress depending on applied magnetic fields can be employed to develop many controllable devices one of them being MR fluid based clutches. One major problem however with MR fluid based clutches is that at high rotational speeds, the iron/ferrous particles in the MR fluid centrifuge due to very high centrifugal forces. Thus the particles move outward as the speed increases thereby making the fluid non-homogeneous. Many times however the initial analysis assumes fluid homogeneity, which is really not the case. In this paper this problem is addressed by assuming various volume fraction profiles describing the fluid particle orientation. Two cases, one with a linear profile and the other with an exponential profile are discussed. Expressions for the torque transmitted are derived at for both disc shaped and cylindrical shaped clutches. In addition, the use of a MR sponge based clutch that may indeed reduce the effect of centrifugal forces significantly is described. The design methodology and configuration for the sponge clutch are also discussed. An experimental set up used to test the clutch is also described.

Study on Design Method for Magneto-Rheological Fluid Damper Based on Squeeze Mode and Experimental Tests

2011 ◽  
Vol 199-200 ◽  
pp. 97-101 ◽  
Author(s):  
Chang Rong Liao ◽  
Li Juan Fu ◽  
Ying Yang
Keyword(s):  
Analytical Method ◽  
Vibration Isolation ◽  
Squeeze Flow ◽  
Damping Force ◽  
Mr Fluid ◽  
Isolation System ◽  
Technical Requirements ◽  
Fluid Damper ◽  
Magneto Rheological ◽  
Mr Fluid Damper

A Magneto-rheological(MR) fluid damper based on squeeze model is put forward. The squeeze flow differential equation is obtained. Navier slip condition is considered on two boundary surfaces and compatible condition is established. The radial velocity profile and the radial pressure distributions are derived respectively. The mathematical expression of damping force is devloped. In order to verify rationality of analytical method, MR fluid damper based on squeeze mode is designed and fabricated according to technical requirements of engine vibration isolation system. The experimental damping forces from MTS870 Electro-hydraulic Servo with sine wave excitation show that analytical method proposed in this paper is feasible and has the reference value to design MR fluid damper based on squeeze mode.

PREPARATION AND ABRASION PROPERTIES OF MAGNETO-RHEOLOGICAL FLUID OF DISPERSED SILICA-COATED IRON

2005 ◽  
Vol 19 (07n09) ◽  
pp. 1121-1127 ◽  
Author(s):  
A. SHIBAYAMA ◽  
T. OTOMO ◽  
Y. AKAGAMI ◽  
K. SHIMADA ◽  
T. FUJITA
Keyword(s):  
Carbonyl Iron ◽  
Spherical Particles ◽  
Fluid Viscosity ◽  
Iron Particles ◽  
Mr Fluid ◽  
Abrasion Test ◽  
Silicon Oil ◽  
Mr Fluids ◽  
Transmission Oil ◽  
Magneto Rheological

In this study, a magneto-rheological fluid dispersed by silica-coated iron was developed and its properties such as fluid viscosity (shear stress or shear rate) and abrasion were investigated. The metallic iron coated by silica dispersed in magneto-rheological fluid was prepared by H 2 reducing of precipitated magnetite ( Fe 3 O 4). Then, the magneto-rheological fluid (MR fluid) for the seal was prepared with silica-coated iron or carbonyl iron (HQ type; diameter of 1.6-1.9 10-6m) and two solvent oils i.e. silicon oil (SH200cv, 10000cSt) and CVT oil (T-CVTF, automobile transmission oil). It was observed that the MR fluid viscosity of CVT oil with HQ particles is lower in every fluid condition. Furthermore, the surface roughness of polyvinyl plate after abrasion test for MR fluid with silica coated iron and CVT oil as solvent was higher compared to the other types of MR fluids. The results indicated that carbonyl iron (spherical particles) and silica-coated iron particles dispersed in silicon oil are feasible to be used where the low abrasion in mechanics is required.

Passenger Comfort Analysis in an Automotive Considering a Magneto-Rheological Damper based Suspension

2017 ◽  
Vol 8 (4) ◽  
Author(s):  
R.B. Soujanya ◽  
D.D. Jebaseelan ◽  
S. Kannan
Keyword(s):  
Ride Comfort ◽  
Mr Damper ◽  
Nonlinear Behaviour ◽  
Passive Damping ◽  
Damping Force ◽  
The Road ◽  
Mr Dampers ◽  
Moving Vehicles ◽  
Magneto Rheological ◽  
Multi Body

Passenger’s comfort in moving vehicles depends on the quality of the ride. The major cause of discomfort is the vibration transmitted to passengers due to the road irregularities. For a comfortable ride on a vehicle, vibration must stay within prescribed standards. In the present work, an attempt was made to show that, the vibrations can be limited with the use of Magneto-rheological (MR) dampers for varying road profiles than the passive damping methods. MR dampers are semi-active control devices that use MR fluids to produce controllable damping force as they are known to exhibit nonlinear behaviour. Multi body dynamic studies were done to study the response of the system using a quarter car model. In this paper, passive damping (viscous damping) was considered at natural frequency of 1.012Hz, the response of damping was observed after 10s and the acceleration was found to be 6m/s2. When MR damper is employed as the magnetic force increases, the response of the damping was better than the passive damping, at 1.2A it comes down to 0.55m/s2, and the vibration gets dampened after 1.75s. Hence, from this study it is concluded that the MR damper can be employed in automobile for better ride comfort.

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