Vibration suppression is considered as a keyresearch field in civil engineering to ensure the safety and comfort of their occupants and users of mechanical structures. To reduce the system vibration, an effective vibration control with isolation is necessary. Vibration control techniques have classically been categorized into two areas, passive and active controls. For a long time, efforts were made to make the suspension system work optimally by optimizing its parameters, but due to the intrinsic limitations of a passive suspension system, improvements were effective only in a certain frequency range. Compared with passive suspensions, active suspensions can improve the performance of the suspension system over a wide range of frequencies. Semi-active suspensions were proposed in the early 1970s [1], and can be nearly as effective as active suspensions. When the control system fails, the semi-active suspension can still work under passive condition

1. DESIGN AND FABRICATION OF VIBRATIONAL PLATFORM WITH
MAGNETO – RHEOLOGICAL DAMPER
TITLE
SUBMITTED BY
NAME: JABBAR ALI.A
REG.NO: 210421402003
GUIDE:Dr.A.RAMESH M.E Ph.D,

2. INTRODUCTION
A vibrational platform with an MR (magneto-rheological) damper is a
device used to study the dynamic behavior of mechanical systems
subjected to vibration. The platform is designed to simulate a wide
range of vibration frequencies and amplitudes, while the MR damper
provides a variable damping force that can be adjusted in real-time.The
design of the vibrational platform involves selecting appropriate
materials and components, such as the vibration generator, actuator, and
control system. The platform must be sturdy and capable of
withstanding the high forces and accelerations that occur during testing.

3. MR Fluid
1. MR fluid is composed of micron-size magnetizable particles, some
kind of surfactant and carrier fluid. When exposed to a magnetic
field, these particles are polarized and attract each other in
accordance with the magnetic line as shown in figure 1, resulting in
chains of particles within the fluid and raising the viscosity of fluid.
The fluid is thus converted from the liquid state to glue type one
like peanut butter, at a rapid speed (in milliseconds) and reversibly.
2. The MR fluid used in this research is made in the Civil Engineering
Department of Cheng-Kung University (NCKU), Taiwan. The size
of magnetizable particles is seven micrometers in average diameter
and the carrier fluid is 1000 cps (1Pa·s=1N·s/m2=1000cps) of
silicone glue. One proprietary additives of surfactant is adopted to
keep magnetizable particles floatable, so the appearance of this MR
fluid is even dark gray and sensitive to the magnetic field. The
formula of MR fluid used in this research is 30% seven micrometers
magnetizable particles, 8% surfactant and 62% silicone glue of 1000
cps.

4. MR Damper
1. Using MR fluid to provide controllable damping force, MR damper is one
kind of semi-active control devices. It is quite promising for civil
engineering applications because of its many attractive features such as
small power requirement, reliability, and inexpensiveness to manufacture
(Ginder et al. 1996; Kamath and Wereley 1997; Dyke et al. 1998).
2. The MR damper investigated in this research is a prototype one developed
under Department of Civil Engineering of NCKU. The semi-active control
device of MR damper is usually retrofitted from passive control device of
fluid damper. The dampers in figure 2 are fluid dampers designed and
manufactured around seven years ago.
3. A plastic tube entwining enamelled wire as shown in figure 3 is designed
so as to generate the magnetic field. This is a particular particle of MR
damper developed in this research and the dimensions are
4. shown in figure 4. For the nominal design, a maximum damping force of
200,000 N (20 tons), the effective fluid orifice is the entire annular space
between the piston outside diameter and the inside of the damper cylinder
housing.

5. MR DAMPER IMAGES

7. PERFORMANCE TEST
The experimental setup is constructed at the laboratory for MR damper
testing. The MR damper is attached to an about 4 meters height material test
control system as shown in figure 7.Force-displacement and force-velocity
tests under sinusoidal displacement excitation are conducted to investigate
the fundamental behavior of the MR damper. In this experiment, 1.0, 3.0
and 5.0 mm amplitudes sinusoidal displacement excitations at frequencies
of 0.1, 0.3 and 0.5 Hz are employed. The input voltage to the damper coil is
constant at 0, 30 and 47 V, respectively.The effects of changing input
voltage are readily observed. As the input voltage increases, the force
required to yield the MR fluid in the damper also increases, and a plastic-
like behavior is shown in the hysteresis loops.

8. FABRICATION
The fabrication of an MR (magneto-rheological) damper typically
involves the following steps:
Design: The first step in the fabrication of an MR damper is to design the
damper based on the specifications required for the intended application.
This includes selecting the appropriate materials, dimensions, and
magnetization requirements.
Component fabrication: The components of the damper are fabricated,
typically using CNC machines or other precision manufacturing
techniques. These components may include the cylinder, piston, and valve
components.

9. Fluid preparation: The MR fluid used in the damper is
prepared according to the required specifications. This
involves mixing a carrier fluid (such as oil) with
magnetizable particles (such as iron or nickel) and any
necessary additives to achieve the desired properties.
Assembly: The components of the damper are
assembled together, with the MR fluid added to the
damper as part of this process. The assembly process
may include filling the damper with the MR fluid,
installing seals, and attaching the piston and valve
components.
Testing: Once the damper is assembled, it undergoes
testing to ensure that it meets the required specifications.
This may involve measuring the damping force,
response time, and temperature range of the damper,
among other parameters.

10. APPLICATIONS
MR (magneto-rheological) dampers have a wide range of
applications in various industries and systems, including:
Automotive: MR dampers are commonly used in automotive
suspension systems to provide improved ride comfort and
handling performance. They can adapt quickly to changes in
road conditions, providing a smoother and safer ride.
Civil engineering: MR dampers can be used in the design of
buildings and other structures to reduce the impact of
earthquakes, wind, and other external forces. They can also be
used to dampen vibrations caused by foot traffic, wind, and
other factors.
Aerospace: MR dampers can be used in aerospace applications
to provide precise control of structural dynamics, such as in
aircraft wings and other moving parts. They can also be used to
reduce vibrations caused by engine or aerodynamic forces.

11. THANKING YOU