The document discusses vibration isolation methods used in various industries. It describes passive isolation systems like pneumatic isolators, mechanical springs, elastomeric pads, and negative-stiffness isolators. Active isolation systems contain sensors, controllers and actuators to strongly suppress vibrations. Semi-active systems consume less power than active systems but provide more control than passive isolators. The document also reviews several research papers on practical vibration control methods, noise isolation in automotive industry, foundations for industrial machines, and adaptive control for payload launch vibration isolation.

1. VIBRATION ISOLATION METHODS IN VARIOUS INDUSTRIES
Group Members:
Lalit Jadhav TE 08
Yash Channe TE 05
Swaraj Aswar TE 06
Tanish Balbudhe TE 07
Guided by- Prof. Shailendra Shisode
DYNAMICS OF MACHINERY

2. INTRODUCTION
1. Vibrations are produced in machines having unbalanced masses. High
vibration means high chances of machine failure.
2. So vibration isolation of machines is preferred in industries for long life of
machines.
3. Vibration isolation is the process of isolating an object, such as a piece of
equipment, from the source of vibrations and its effectiveness is measured
in terms of force or motion.
4. Objectives:
● To protect delicate machine from excessive vibrations.
● To prevent vibratory forces coming from machine to transmit them to
its foundation.

3. VIBRATION ISOLATION METHODS
● Pneumatic or air isolators:
○ These are bladders or canisters of
compressed air.
○ A source of compressed air is required to
maintain them.
○ Air springs are rubber bladders which
provide damping as well as isolation and are
used in large trucks.
A) Passive isolation systems

4. b) Mechanical springs and
spring-dampers:
● These are heavy-duty isolators used
for building systems and industry.
● Sometimes they serve as mounts for
a concrete block, which provides
further isolation.

5. c) Pads or sheets of flexible materials such as
elastomers, rubber, cork, dense foam and
laminate materials:
● Elastomer pads, dense closed cell
foams and laminate materials are often
used under heavy machinery, under
common household items, in vehicles
and even under higher performing
audio systems

6. d) Negative-stiffness isolators:
● Negative-stiffness isolators are less
common than other types and have
generally been developed for
high-level research applications such
as gravity wave detection.

7. e) Wire rope isolators:
● These isolators are durable and can withstand extreme environments. They are
often used in military applications.
f) Base isolators for seismic isolation of buildings, bridges:
● Base isolators made of layers of neoprene and steel with a low horizontal
stiffness are used to lower the natural frequency of the building.
g) Tuned mass dampers:
● Tuned mass dampers reduce the effects of harmonic vibration in buildings or
other structures.

8. B) Active isolation
● Active vibration isolation systems contain, along with the spring, a feedback
circuit which consists of a sensor , a controller, and an actuator.
● The acceleration (vibration) signal is processed by a control circuit and amplifier.
● Then it feeds the electromagnetic actuator, which amplifies the signal. As a result
of such a feedback system, a considerably stronger suppression of vibrations is
achieved compared to ordinary damping.
● Active isolation today is used for applications where structures smaller than a
micrometer have to be produced or measured.

9. ● Sensors for active isolation:
○ Piezoelectric accelerometers and force sensors
○ MEM accelerometers
○ Geophones
○ Proximity sensors
○ Interferometers
● Actuators for active isolation:
○ Linear motors
○ Pneumatic actuators
○ Piezoelectric motors

10. Semi-active isolation
Semi active vibration isolators have received attention because they consume less
power than active devices and controllability over passive systems.

11. RESEARCH PAPERS
A) Practical Methods for Vibration Control of Industrial Equipment by Andrew
K. Costain, B.Sc.Eng. and J Michael Robichaud, P.Eng. Bretech Engineering Ltd.
● Abstract :
○ It gives the different methods for isolation like
○ Force Reduction of excitation inputs due to, for example, unbalance or
misalignment, will decrease the corresponding vibration response of the
system.
○ Mass Addition will reduce the effect (system response) of a constant
excitation force.
○ Tuning (changing) the natural frequency of a system or component will
reduce or eliminate amplification due to resonance.

12. B) Application of Elastomeric Components for Noise and Vibration Isolation
in the Automotive Industry.
Authors- Craig Lewitzke, Ping Lee
Event- SAE 2001 Noise & Vibration Conference & Exposition
● Abstract-
○ Elastomeric isolators are used in a variety of different applications to reduce
noise and vibration.
○ Paper discusses about fundamentals of vibration isolation, stiffness and
damping measurement, rubber technology, etc. also they have given SAE
VIBRATION ISOLATOR TESTING GUIDELINES also.

13. C) FOUNDATIONS FOR INDUSTRIAL MACHINES AND EARTHQUAKE
EFFECTS
Authors- K.G. Bhatia
Publication- ISET Journal of Earthquake Technology, Paper No. 495, Vol. 45,
No. 1-2, March-June 2008
● Abstract:
○ It gives idea about vibration isolation(page no-25).
○ Also it focuses on isolation efficiency, selection of isolators and isolation
requirements with appropriate sketches.

14. D) Adaptive control for payload launch vibration isolation
Authors: Julian R. Jarosh; Gregory S. Agnes; Gregory G. Karahalis
Event: SPIE's 8th Annual International Symposium on Smart Structures and
Materials, 2001, Newport Beach, CA, United States
● Abstract-
○ It mainly focuses on study of vibrations occurs during rocket propulsion and
various ways to reduce it using vibration isolators.
○ It aims to enhance the reliability and lifetime of propulsion system and try to
decrease the payload structural mass.

15. REFERENCES
Introduction- https://en.m.wikipedia.org/wiki/Vibration_isolation
Research Papers-
A) http://www.uoxray.uoregon.edu/ph351/mass_damping.pdf
B) https://www.sae.org/publications/technical-papers/content/2001-01-1447/
C) https://www.iitr.ac.in/iset/pages/files/March_June_2008_Issue.pdf#page=14
D) https://www.spiedigitallibrary.org/conference-proceedings-of-spie/4331/0000/Ad
aptive-control-for-payload-launch-vibration-isolation/10.1117/12.432700.short
Book- Industrial noise control and acoustics by By Randall F. Barron(CRC press)