This document describes the design and testing of a magneto-rheological damper for vehicle suspension. It begins with an introduction to suspension systems and defines the problem of conventional passive suspension. The objectives are then outlined as designing an MR damper to improve ride comfort and stability. Details are provided on MR fluids, literature reviews on previous MR damper designs, and the project methodology. The damper is modeled and parameters such as dimensions and materials are selected. The damper is manufactured using various machining processes and tested on a compression testing machine while supplying different currents. Test results show the damper's force increases with current, demonstrating the variable viscosity provided by the MR effect. The conclusions determine the damper's performance met objectives

1. Design and Testing of
Magneto-Rheological Damper
for Vehicle Suspension
TEAM GUIDE
Anirudh B.A 1VA14ME002 Deepak C
Ghanashyam U.S 1VA14ME013 Assistant Professor
Nagesh N 1VA14ME028 Dept. of ME
Rahul S 1VA14ME039 1
SAI VIDYA INSTITUTE OF TECHNOLOGY
(Affiliated to Visvesvaraya Technological University, Belagavi)
Rajanukunte, Bengaluru - 560064
PROJECT PRESENTATION ON

2. OVERVIEW
1. Introduction
2. Problem Definition
3. Objectives
4. Magneto Rheological Fluids
5. Suspension System
6. Literature Survey
7. Methodology
8. Block Diagram
9. Mathematics Behind MR Damper
10. Design Parameters of Damper
11. Modeling
12. Material Selection
13. Machining Process
14. Testing Procedure
15. Results and Discussion
16. Conclusion
17. Future Scope
18. References
2

3. INTRODUCTION
3
 Supports weight of the vehicle.
 Provides smoother ride for the driver and passengers i.e. acts as
cushion.
 Protects your vehicle from damage and wear.
 It also plays a critical role in maintaining control stability.
 It also keeps the wheels pressed firmly to the ground for
traction.

4. PROBLEM DEFINITION
 Conventional suspension system is specified in terms of
viscosity of the damper which cannot be changed.
 Force transmitted to the rider by the conventional
suspension system is slightly high.
 Existing suspension system are passive in nature.
 The ride comfort and stability of the motorcycle is greatly
affected.
4

5. OBJECTIVES
 Review of theoretical and experimental research work on MR fluid
based shock absorber.
 Design of suitable damper to meet the requirements.
 To machine the damper according to the design made.
 Commission the damper for performance and make it leak proof.
 To conduct performance test at different operating conditions.
 To achieve improvement in force transmission and displacement.
 To reduce the shock experienced at the rider end.
5

6. MAGNETORHEOLOGICAL FLUIDS
 Magnetorheological (MR) materials are a class of materials whose
rheological properties may be rapidly varied by applying a magnetic
field. This change is in proportion to the magnitude of the magnetic
field applied and is immediately reversible.
 MR material behavior is often modeled by the Bingham plastic model.
Advances in the application of MR materials are parallel to the
development of advanced MR materials. These applications include
brakes, dampers, and shock absorbers.
 Most commonly, these materials are fluids that consist of micron-
sized, magnetically polarizable ferrous particles suspended in a
carrier liquid.
6

7. LITERATURE SURVEY
 Sadok Sassi, Khaled Cherif [1] paper tries to increase the damping coefficient up to
3 times for an excitation current of only 2 amps using four coil setup . Final aim is
to optimize the dynamic response and provide experimental verification of the
same.
 J Wang and G Meng [2] have discussed the single-ended piston rod arrangement for
vehicle seat suspension. The damper designed is 41 mm in diameter, has a 179mm
eye-to-eye length at mid-stroke and has a 29mm stroke. It contains 70ml of MR
fluid and power required is only 5 A. Finally the author aims to evaluate these
dampers for wide range of applications.
 Ying-Qing Guo and Wei-Yang Guo [6] have discussed about preparation and
experimental study of MR fluids in their paper. Using 3µm CI particles and 10µm CI
particles MR fluids which are synthetic oil based were prepared in 4 samples
whose CI particles mass fraction was about 80%.
 Nicola Golineli and Andrea Spaggiari [10] have designed and manufactured a novel
Magneto-Rheological fluid damper with internal pressure control. The damper
specifications are 40mm cylinder diameter, 2A max current, 50mm stroke and max
force is 2000N. The prototype of the damper is presented by the authors for
further optimization and commercialization.
 Chetan S More, Vaibhav R Swalak, Ajinkya R and TB Patil [11] have tested the
damper using a Universal Testing Machine (UTM) where they have used a current
supplying source to vary the current and have mounted the damper in the UTM
using specific fixtures and applied compressive loads for each current. They have
plotted a graph of Force vs Displacement for each current which indicates the
change in viscosity and displacement according to change in current. 7

8. METHODOLOGY
8
Modeling
Material
Selection and
Designing
Manufacturing
Experimental
set-up
Testing

9. BLOCK DIAGRAM OF MR DAMPER
9

10. DESIGN PARAMETERS OF DAMPER
Parameters Symbol Value
Desired damping force
Available maximum current
Coil turn number
Gap size
Inner radius of the casing
Outer radius of the casing
Outer radius of piston
Radius of piston rod
Radius of yoke core
Length of magnetic pole
Length of yoke core
Coil diameter
Electric resistance of the
coil
Initial gas pressure
Initial gas volume
Fdes
Imax
N
h
ri
ro
rp
rs
rc
lp
lc
-
-
Pg0
Vg0
2000N
5.0A
80
1.0mm
22.0mm
23.0mm
21.0mm
5.0mm
16.2mm
10.0mm
10.0mm
0.5mm
1.24Ω
10 bar
11634 mm3
10

11. MODELING
11

12. MATERIAL SELECTION
 Mild Steel (MS) for the cylinder of grade EN8 or SS41, a ferromagnetic
material
 Tensile strength up to 550MPa and yield strength up to 280MPa
 Magnetic properties of the yoke used for the MR dampers
12
Standard Grade Carbon Manganese Phosphorous Sulphur Silicon
BS 970 EN8/080M40 0.36-0.44 0.60-1.00 0.05 0.005 0.10-0.40
Property Value
Bs,sat 1.326T
Hs,sat 1.989A/mm

13. MATERIAL SELECTION
 Aluminum caps were used to reduce weight of the damper . As these caps are
not subjected to tension or compression during the testing phase .
 Selection of cap material for real time application is left for future scope .
 Electromagnet circuit design
 Teflon material is used for the floating piston which is a part of accumulator
design.
13
Amperage
wire gage
no.
Bare wire
dia(mm)
Insulated
wire
dia(mm)
Max no. of
turns
Max
Current
(A)
Resistance
of the
coil(Ω)
26 0.40 0.46 80 5 1.27

14. MACHINING PROCESSES
 Turning
 Cylindrical grinding
 Honing
 Welding
 Surface grinding
 Thread Cutting
 Milling
 Grooving
14

15. TESTING PROCEDURE
 The test setup consisted of a Compression testing machine with a capacity of
10 ton, a 5V DC battery to supply current to the MR damper and a dial gauge
to record the displacement of the piston.
 The damper has a stroke of ±25mm and was supplied various currents from
0amps to 1amp.
 The damper was placed between the jaws of the machine in its extended
position and due to limitation of the dial gauge displacement of the piston
was constrained to a maximum of 3 mm.
 The hydraulic upper arm applied load on the piston rod and corresponding
displacements were recorded with help of dial gauge. The test setup used is
as shown below
15

16. RESULTS AND DISCUSSIONS
16
• The above graphs represent load v/s displacement of the M R damper
when the current is varied from 0 amp to 1 amp.
• As evident from the graphs the load applied has increased for the same
displacement with increase in current.
• Hence there is a change in the viscosity of the fluid with increase in
current which in turn increases the damping force.
• The graph to the right shows load v/s current , at the max current of 1
amp the damper has absorbed a maximum load of 140kgf or 1373N.

17. CONCLUSION
 As is evident from above graphs of load v/s displacement , when there is
variation in current , extra load is taken by the damper to produce the same
displacement which is the proof of variable viscosity.
 This variable viscosity is achieved due to the MR effect that takes place
inside the damper.
 The stiffening and softening of the damper can thus be achieved with
variations in current.
 By further reducing the cross sectional area of the yoke through which the
magnetic flux passes the characteristics of the damper can be improved.
 It is expected that the proposed design methodology can be used as basic
material for expanding application fields of the MR damper.
17

18. FUTURE SCOPE
 By incorporating sensors like displacement sensor, hall sensor, accelerometer
etc. these dampers act as active suspension system.
 These dampers not only find their application in automobile industry but also
extend their uses in other areas such as prosthetic limbs, earthquake
dampers, aircraft industry for isolating vibrations from aircraft structures and
Aircraft Landing Gears.
 To produce these current variations at the required time, several sensors such
as accelerometer , displacement sensor and a micro-controller with skyhook
algorithm is necessary.
18

19. REFERENCES
[1] “An innovative magnetorheological damper for automotive suspensions: from design to experimental
characterization” by Sadok Sassi, Khaled Cherif.
[2] “Magnetorheological fluid devices: principles, characteristics and application in mechanical engineering”
by J Wang and G Meng.
[3] “A Magnetic Design Method of MR Fluid Dampers and FEM Analysis on Magnetic Saturation” by H.H. Zhang,
C.R. Liao.
[4] “Dynamic performance evaluation of 200KN magnetorheological damper” by Hideo FUJITANI and Hiroshi
SODEYAMA.
[5] “Analytical model of a Magnetorheological damper and its application to its vibration control” by Gongyu
PAN, Hiroshi MATSUIHISA, Yoshihisa HONDA.
[6] “Preparation and Experimental Study of Magnetorheological Fluids for Vibration Control” by Ying-Qing
Guo and Wei-Yang Guo.
[7] “A review on the magnetorheological fluid preparation and stabilization” by M. Ashtiani, S.H.
Hashemabadi, A. Ghaffari.
[8] “Optimal design of a double coil magnetorheological fluid damper with various piston profiles” by
Guoliang Hu, Zheng Xie, Weihua Li.
[9] “Variable magnetic damper for semi-active suspension system” by Vamshi Krishna Dommeti and N Sai
Prabhu.
[10] “Design of a novel magnetorheological damper with internal pressure control” by Nicola Golinelli,
Andrea Spaggiari.
[11] “Vibration reduction by using Magnetorheological damper” by Chetan S More, Vaibhav R and TB Patil.
19

20. CONFERENCE AND PUBLICATION
 We have presented the work at “National Conference on Recent Trends in
Mechanical Engineering and Applied Science 2018” organized by Sri Krishna
Institute of Technology.
 Technical Paper on this project has been accepted for publication and is in
queue for the same in the journal “International Journal of Innovative
Research in Science, Engineering and Technology” .
ISSN (Online): 2319-8753
ISSN (Print): 2347-6710
 Abstract of the Project work has been accepted by the reviewing committee
of “2nd international conference on Recent emerging Engineering Trends in
Mechanical and Civil” being organized by Reva University.
 Technical paper on the project is published in the journal “International
journal of emerging technologies and innovative research”
ISSN: 2349-5162
20

21. Thank You
21