Project report on Adaptive Tuned Dynamic Vibration Absorber

Dr. AMBEDKAR INSTITUTE OF TECHNOLOGY
(An Autonomous Institution, Aided by Government of Karnataka, Affiliated to VTU, Belgaum)
Near Janana Bharathi Campus, Mallathahalli, Bangalore-560056
DEPARTMENT OF MECHANICAL ENGINEERING
MINI PROJECT REPORT ON
"ADAPTIVE TUNED DYNAMIC VIBRATION ABSORBER"
Submitted in partial fulfillment of the requirements for the award of degree in
BACHELOR OF ENGINEERING IN MECHANICAL ENGINEERING.
SUBMITTED BY
KISHAN A. 1DA17ME067
MUKUL R. 1DA17ME093
RAKSHITHA.V 1DA17ME125
RUPESH SHRESTHA 1DA17ME130
UNDER THE GUIDANCE OF
TEJESH S.
Assistant Professor
Department of Mechanical engineering
Dr. Ambedkar Institute of Technology
2020

Dr. AMBEDKAR INSTITUTE OF TECHNOLOGY
(An Autonomous institution, Affiliated to VTU, Belgaum and Aided by Govt. of Karnataka)
Near Janana Bharathi campus, Bangalore -560056
DEPARTMENT OF MECHANICAL ENGINEERING
CERTIFICATE
This is to certify that the project work title “ADAPTIVE TUNED DYNAMIC
VIBRATION ABSORBER” is carried out by KISHAN A (1DA17ME067), MUKUL
R (1DA17ME093), RAKSHITHA.V (1DA17ME125), RUPESH SHRESTHA
(1DA17ME130) bonafide student of Dr. Ambedkar Institute of Technology, Bangalore-
560056, under the guidance of Prof. TEJESH S during the academic year 2020 and is in
partial fulfillment for the award of Degree in Bachelor of Engineering in MECHANICAL
from Dr. Ambedkar Institute of Technology, Bangalore-560056. It is certified that all
corrections/suggestions indicated during internal assessment have been incorporated in the
report deposited in the department. It is further certified that this work has not been submitted
to any university/organization for the award of any other degree or diploma or certificate
including a similar degree. The project report has been approved as it satisfies the academic
requirements in respect of project work prescribed for the Bachelor of Engineering Degree.
Signature of the Guide Signature of the HOD Signature of the Principal
TEJESH S. Dr. T. N. RAJU Dr. C. NANJUNDASWAMY
External Viva:
Name of the Examiners: Signature with date
1.
2.

DECLARATION
Aided By Govt. of Karnataka
We, Kishan A, Mukul R, Rakshita V and Rupesh Shrestha the students of sixth
semester B.E, Mechanical engineering, Dr Ambedkar Institution of Technology,
Bangalore. Hereby declare that the project “ADAPTIVE TUNED DYNAMIC
VIBRATION ABSORBER” has been carried out by us and submitted in the partial
fulfillment for the award of degree of bachelor of engineering in mechanical engineering.
We do declare that this work is not carried out by any other students for the award of degree
in any other branch.
KISHAN A 1DA17ME067
MUKUL R 1DA17ME093

ACKNOWLEDGEMENT
The satisfaction that accompanies the successful completion of this project would be
incomplete without the mention of the people who made it possible, without whose constant
guidance and encouragement would have made our efforts go in vain.
We consider ourselves privileged to express our gratitude and respect towards all
those who have guided us through the completion of the project, “ADAPTIVE TUNED
DYNAMIC VIBRATION ABSORBER”.
As a token of gratitude, we would like to acknowledge our sincere gratefulness to our
guide TEJESH S, Assistant Professor, Department of ME, Dr. AIT, for his unlimited support,
inspiration and encouragement provided throughout the process.
We would like to express our profuse gratitude to Dr. T. N. RAJU, HOD,
DEPARTMENT OF MECHANICAL ENGINEERING, Dr. AIT, for giving us the support,
encouragement and providing us the required lab facilities that was necessary for the
completion of the project.
We also express our gratitude and sincere thanks to all teaching and non-teaching
staff of MECHANICAL DEPARTMENT.
Finally, yet importantly, we would like to express our heartfelt thanks to our beloved Parents
for their blessing and our friends for their help and wishes for the successful completion of
this project report.
KISHAN A 1DA17ME067
MUKUL R 1DA17ME093

ABSTRACT
Vibration is essential as it is one of the ways of energy transmission but undesirable vibration
may lead to catastrophic failures in case of mechanical systems. Nowadays in every
mechanical industrial field, the most important key item to be research is to eliminate or to
control a system’s vibrations. In spite of this, the destructive and undesirable vibrations will
have detrimental effect on the main system, it will also have negative impact on all machinery
equipment, these undesirable vibrations which might be created due to many causes like
unbalanced machinery parts, dry friction between two mating surfaces may create micro and
macroscopic effects on the system and its surroundings. Existing vibration absorbers like one
dynamic vibration absorbers with one or two degree of freedom has to be adjusted manually
which is a great disadvantage. So this is where adaptive tuned dynamic vibration absorber
comes to picture. It’s a dynamic vibration absorber with two degree freedom built in such a
way that it adapts itself to the fluctuating load in the system in order to control the vibration.
The machine component like pump or motors, or compressor etc. would be fixed (lying) on
simply supported beam in our model. Any machine component usually creates undesirable
vibrations which would be transferred to the simply supported beam. To dampen and absorb
it, a secondary mass and spring system is added, which matches the natural frequency of
secondary mass and spring system with that of undesired vibration frequency and hence
dampens the vibration. Here absorber system has cantilever beam on two sides of a cube with
masses placed on it and is fixed to the vibration creating machine. But when the load varies
the vibration frequency varies, hence masses needs to be shifted either towards or away from
centre position. This is done by using slider crank mechanism fitted to the servomotor or
actuator. The accelerometer is placed on simply supported beam or machine component to
measure the vibration rate and through the help of processor the slider crank mechanism
actuator is operated to place the mass until the optimizing situation occur. We have designed
and fabricated the model to demonstrate the working of it in a metallic frame that can be
placed on any flat surface or the ground. We have used the widely used CATIA V5 software
to design the model, Hypermesh, ANSYS APDL and ANSYS Workbench to do the structural
and frequency analysis of the system.
In this project we have designed the dynamic vibration absorbing system to adapt itself to
absorb and control the undesirable vibration of the machine component using slider crank-
mechanism. The model designed by us is compared to the existing model done in the journals
to ensure the improvisation and development of the system in new way.

Table of Contents
Page No:
Chapter 1: INTRODUCTION..............................................................................................................................1
1.1 Vibrations ..................................................................................................................................................1
1.2 Types of Vibration.....................................................................................................................................1
1.3 Causes of Vibration ...................................................................................................................................2
1.4 Damping ....................................................................................................................................................3
Chapter 2: LITERATURE STUDY.....................................................................................................................4
2.1 Study..........................................................................................................................................................6
Chapter 3: THEORY BEHIND TUNING OF VIBRATION ..............................................................................7
3.1 Governing Equations for Base Structure ...................................................................................................9
3.2 Governing Equations for Cantilevered Absorber Using Discrete System Method....................................9
3.3 Expected Result .......................................................................................................................................10
3.4 Different Sections of the System .............................................................................................................10
3.4.1 Motor with Rotary Disc above beam................................................................................................11
3.4.2 Speed Control Unit and Exciter Motor.............................................................................................11
3.4.3 Rotary Disc ......................................................................................................................................11
3.4.4 Slider-Crank Mechanism..................................................................................................................11
3.4.5 Kinematics of Slider-Crank Mechanism ..........................................................................................11
3.5 Electronic Section....................................................................................................................................12
3.5.1 Electronic Section’s Duty.................................................................................................................12
3.5.2 Calibration........................................................................................................................................12
3.5.3 Arduino Board..................................................................................................................................13
3.5.3.1 Arduino Pin Diagram ...............................................................................................................13
3.5.3.2 Digital I/Ps ...............................................................................................................................13
3.5.3.3 Arduino Architecture................................................................................................................13
3.5.3.4 Arduino Program......................................................................................................................14
3.5.3.5 Basic Functions of Arduino Technology..................................................................................14
3.5.3.6 Advantages of Arduino Technology ........................................................................................14
3.5.3.7 L293D IC Motor Driver ...........................................................................................................14
3.5.3.7 Tmega 328................................................................................................................................15
Chapter 4: VIBRATION ABSORBERS............................................................................................................16
4.1 Dynamic Vibration Absorbers.................................................................................................................16
4.2 Vibration Measuring Instruments ............................................................................................................17

4.3 Accelerometer..........................................................................................................................................17
4.4 Adaptive Tuned Dynamic Vibration Absorber........................................................................................18
Chapter 5: PROJECT METHODOLOGY.........................................................................................................19
5.1 Introduction..............................................................................................................................................19
5.2 Planning...................................................................................................................................................19
5.2.1 Data Collection.................................................................................................................................19
5.2.2 Software Requirement......................................................................................................................19
5.2.3 Hardware Requirement.....................................................................................................................20
5.2.4 Specification of Component.............................................................................................................20
5.3 Implementation........................................................................................................................................20
5.3.1 Construction .....................................................................................................................................20
Chapter 6: DESIGN, ANALYSIS AND EXPERIMENTATION .....................................................................22
6.1 Materials Required...................................................................................................................................22
i. Rectangular Frame .................................................................................................................................22
ii. Cantilever Beam....................................................................................................................................22
iii. Clamps .................................................................................................................................................22
iv. AC Motor .............................................................................................................................................22
v. Eccentric Mass ......................................................................................................................................22
vi. Spring ...................................................................................................................................................23
vii. Cantilever beam for secondary masses ...............................................................................................23
viii. Secondary Masses..............................................................................................................................23
ix. Slider-Crank Links ...............................................................................................................................23
x. Servomotor............................................................................................................................................24
xi. Accelerometer ......................................................................................................................................24
xii. Arduino ...............................................................................................................................................24
xiii. Dimmer-stat and Tachometer............................................................................................................25
xiv. Batteries and Power Cables................................................................................................................25
6.2 3D CAD Modeling...................................................................................................................................25
6.3 Analysis ...................................................................................................................................................27
6.3.1 Analysis Results based on the Journal..............................................................................................28
6.4 Experimental Results based on the Journal..............................................................................................27
Chapter 7: SUMMARY.....................................................................................................................................29
7.1 Conclusion...............................................................................................................................................30
7.2 Scope for Future.......................................................................................................................................31
REFERENCES ..................................................................................................................................................32

LIST OF TABLES
Page No.:
Table i: Material dimension....................................................................................................................... 22
Table iii: Clamps........................................................................................................................................ 22
Table iv: AC motor.................................................................................................................................... 22
Table v: Eccentric Mass............................................................................................................................. 23
Table vii: Cantilever Beam for Secondary Mass....................................................................................... 23
Table viii: Secondary Mass ....................................................................................................................... 23
Table ix: Slider Crank Links...................................................................................................................... 24
Table x: Servomotor .................................................................................................................................. 24
Table xi: Accelerometer ............................................................................................................................ 24

LIST OF FIGURES
Page No.:
Figure 3(a): Two degrees of freedom system ......................................................................................................7
Figure 3(B): Effect of the dynamic vibration absorber on the response of machine ...........................................9
Figure 3.3: Model of Adaptive tuned dynamic vibration absorber....................................................................10
Figure 3.4.1: Motor with rotary disc and Speed controller................................................................................11
Figure 3.4.5: Slider-Crank Mechanism..............................................................................................................11
Figure 3.5.2: Location of control keys on the electronic circuit ........................................................................12
Figure 3.5.3.3: Arduino Architecture.................................................................................................................13
Figure 3.5.3.7: Pin diagram of L293D IC..........................................................................................................15
Figure 3.6: AT mega 328...................................................................................................................................15
Figure 4.1: Vibration Absorber..........................................................................................................................16
Figure 4.3: Accelerometer .................................................................................................................................17
Figure 4.4: Model of Adaptive Tuned Dynamic Vibration Absorber ...............................................................18
Figure 5.3.1(a): Fabrication of Frame................................................................................................................20
Figure 5.5.1(b): Circuit design for controlling of servomotor using the accelerometer ....................................20
Figure 5.1.12: Arduino UNO.............................................................................................................................23
Figure 6.2(a):The assembled 3D model.............................................................................................................25
Figure 6.2(b) :Front View..................................................................................................................................25
Figure 6.2(c): drawing of assembly (drafting)...................................................................................................26
Figure 6.2(d): servomotor and cantilever beam assembly.................................................................................26
Figure 6.3(a): Structural analysis of cantilever beam ........................................................................................27
Figure 6.3(b): Analysis of rotary disc/eccentric mass........................................................................................27
Figure 6.3.1(a): Model in visualization..............................................................................................................28
Figure 6.3.1(b): Analysis of the rotary disc .......................................................................................................28
Figure 6.3.1(c): Analysis of rotary disc and reaction forces...................................................................................29
Figure 63.1(d): Analysis of the Cantilever bar ................................................................................................. 29
Figure 6.3.1(e): Acceleration differences- results with linear perturbations ........................................................ 29
Figure 6.4: Comparison of different methods to control of vibration................................................................. 30

ADAPTIVE TUNED DYNAMIC VIBRATION ABSORBER
Dr AIT, Dept of ME | 2020 Page 1
Chapter 1
INTRODUCTION
People became interested in vibration when they created the first musical instruments, probably
whistles or drums. Since then, both musicians and philosophers have sought out the rules and
laws of sound production, used them in improving musical instruments, and passed them on
from generation to generation. Most human activities involve vibration in one form or other.
For example, we hear because our eardrums vibrate and see because light waves undergo
vibration. Breathing is associated with the vibration of lungs and walking involves (periodic)
oscillatory motion of legs and hands. Few countries experienced earthquakes, which created
seismic waves. When people started to observe these they later started to think and study about
vibrations and later vibrations developed into an interesting subject among the people.
Although vibration is important for the running of different mechanical systems, it is a
significant destabilizing source that can seriously degrade the operation, lessen the working
life, and, in some cases, lead to catastrophic failure of mechatronic devices. Produced internally
from sources of noise such as motors, bearings and other moving parts as well as from
electrical noise, unwanted vibration should be eliminated or compensated for.
1.1 Vibrations
Vibrations are oscillations of a mechanical or structural system about an equilibrium position.
Vibrations are initiated when an inertia element is displaced from its equilibrium position due
to an energy imparted to the system through an external source. A restoring force, or a
conservative force developed in a potential energy element, pulls the element back toward
equilibrium.
1.2 Types of Vibration
Vibrations in a system can be classified into 3 categories
i. Free and Forced Vibrations
ii. Damped and Undamped Vibraions
iii Deterministic and Random Vibrations
iv. Longitudinal, Transverse and Torsional Vibrations
i. Free and Forced Vibrations
When no external forces acts on the body after giving it an initial displacement, then the body
is said to be under free or natural vibration. Eg: Oscillation of a simple pendulum.
When the body vibrates under the influence of external force then the body is said to be under
forced vibration. Eg; Machine tools, electric bells.
ii. Damped and Undamped Vibrations

If the vibratory system has a damper then there is a reduction in amplitude over every cycle of
vibration since the energy of the system will be dissipated due to friction this type of vibration
is called damped vibrations.
If the vibratory system has no damper then the vibration is called undamped vibration.
iii. Deterministic and Random Vibrations
If the vibrations of the excitation force or motion acting on a vibratory system is known then
the excitation is known as deterministic. The resulting vibration is called the deterministic
vibration.
If the magnitude of excitation force or motion acting on a vibratory system is unknown, but the
averages and deviation are known then the excitation is known as non-deterministic. The
resulting vibration is called random vibration.
iv. Longitudinal, Transverse and Torsional Vibrations
When the particles of the shaft or disc moves parallel to the axis of shaft, then the vibrations
are known as longitudinal vibrations.
When the particles of the shaft or discs moves approximately perpendicular to the axis of the
shaft, then the vibrations are known as transverse vibrations.
When the particles of the shaft or disc moves in a circle about the axis of the shaft, then the
vibration are known as torsional vibrations.
1.3 Causes of Vibration
Most vibrations are undesirable as they produce excessive stresses, energy losses, increase
bearing loads, induce fatigue, undesirable noise, partial or complete failure of parts etc.
i. Alignment problems: When two or more rotating machines are connected, the
correct alignment is crucial.
If the shafts centre lines are parallel but not in line leads to parallel misalignment.
If the shafts meet at a point, but are not parallel leads to angular misalignment.
A combination of both angular and parallel misalignment is common.
ii. Unbalance: When the centre of gravity of a rotating object is not exactly in the centre
line, it causes machine unbalance resulting in vibration. When a machine is
unbalanced, it can cause damage to the machine itself, the foundation pipes etc.
iii. Resonance: Every machine has one or more resonance frequencies (natural
frequency). When a rotation frequency coincides with the resonance frequency of the
machine, resonance occurs. Resonance can have major impact.
iv. Loose parts: Loose bearings, loose belts, and corrosion can cause the machine to
vibrate excessively. Due to the mechanical forces in the machine, dynamic unbalance
is the most common type of unbalance and the result of static and coupled unbalance.

v. Bearing damage: In rotating machinery, we come across two main types of bearings,
Roller bearing gets damaged due to the usage of roller. Sleeve bearings do not use a
rolling element, but uses a fluid film to reduce friction. Vibrations can be caused by
inaccuracies in the fluid film; if a stable oil film cannot be formed, it can break,
resulting in a oil whip or oil whirl.
vi. Damaged or worn out gears: Gearbox vibrations are often caused by damaged or
worn out gear teeth. When the gear tooth engagement involves a damaged tooth, the
force cannot be transferred as with the other gears tooth engagement. If a gear tooth is
broken, less force can be transferred at this point of the cycle. Vibrations occurs as a
result.
1.4 Damping
Damping is one of the most effective methods of controlling vibrations. It is a process that
converts vibrational energy into heat, eliminating the vibrational energy through friction and
other processes.
Increasing damping or stiffness can both reduce resonant vibration and the resulting noise by
preventing the vibration from travelling through the structure.
Why is damping important?
Appliances, equipment, generators and other mechanical structures are capable of producing a
great amount of noise and vibration.
Vibrational energy can be problematic for variety of reasons;
i. It can make washing machines, blenders, vacuums noisy and disruptive for users
ii. Medical equipment can be uncomfortable.
iii. Larger mechanisms like engines, noise and vibration control may be needed in the
engine compartments, enclosures, cab walls, and floors and ceiling systems. This is
because vibration causes instability and fatigue in mechanical structures in addition to
creating noise.
When the manufacturers develop these structures, it’s necessary to decide what type of
damping system to use: free layer damping or constrained layer damping can work well for
most applications, whether industrial, medical, or aerospace, free layer damping has some
limitations.
Chapter 2
LITERATURE SURVEY

Developing a New Design for Adaptive Tuned Dynamic Vibration Absorber
(ATDVA) Based on Smart Slider-Crank Mechanism to Control of Undesirable
Vibrations
Reza Mirsanei, Aidin Hajikhani, Behzad Peykari, Jahanbakhsh Hamedi, Islamic Azad,
University Central Tehran Branch, Department of Mechanical Engineering Niayesh University
Complex, Orag St., Hamila Blvd
When a structure is undergoing some form of vibration, there are a number of ways in which
this vibration can be controlled. Two general types of external dampers may be added to a
mechanical system in order to improve its energy dissipation characteristics. They are:
i. Passive control
ii. Active control
Passive control (Denys, 1999) involves some form of structural augmentation or redesign,
often including the use of springs and dampers that leads to a reduction in the vibration. Active
control (Chu et al., 2005) augments the structure with sensors, actuators and some form of
electronic control system, which specifically aim to reduce the measured vibration levels.
Over the last decade, smart devices have been studied as potential alternatives to the use of
conventional control mechanisms for controlling mechanical vibrations. This research
investigates the use of Adaptive Tuned Dynamic Vibration Absorbers (ATDVA) with smart
slider-crank mechanism to control vibration in a structure (Spencer, 2008).
This study proposes a new design with the use of smart slider crank mechanism. Our purpose
in this scheme is to enhance the accuracy and speed, to control of undesirable vibrations. A
dynamic vibration absorber (DVA) (Den Hartog, 1985) is essentially a secondary mass,
attached to an original system via a spring and damper. The natural frequency of the DVA is
tuned such that it coincides with the frequency of undesirable vibrations in the original system.
Dynamic Vibration Absorbers were first invented in 1909 by Den Hartog. Work on DVAs was
undertaken for the defense mechanism against earthquakes (Bozorgnia, 2004). Much work has
been directed towards the use of DVAs attached to building structures, to counter seismic
movements and wind forces (Samali et al., 2004).
The main function of the Tuneable Dynamic Vibration Absorber is to damp the undesirable
vibration on the system by converting the system from one degree of freedom into the two
degree of freedom, thus the resonance of system in each mode would damp and control. So we
designed and attached an Adaptive Tuned Dynamic Vibration Absorber to the primary system.
Design of a Real-Time Adaptively Tuned Dynamic Vibration Absorber with a
Variable Stiffness Property Using Magnetorheological Elastomer
Institute of Science and Engineering, Kanazawa University, Kakuma-machi, Kanazawa,
Ishikawa 920-1192, Japan
A passive-type dynamic vibration absorber (DVA) is basically a mass-spring system that
suppresses the vibration of a structure at a particular frequency. Since the natural frequency of

the DVA is usually tuned to a frequency of particular excitation, the DVA is especially
effective when the excitation frequency is close to the natural frequency of the structure. Fixing
the physical properties of the DVA limits the application to a narrowband, harmonically
excited vibration problem. The design of the absorber, adhering to a well-known optimal
tuning and damping theory, can extend the effective frequency range [1]. However, the
damping performance remains at a certain level irrespective of whether the vibration is
harmonic or not, and the performance may become worse for vibrations caused by transient
disturbances. A frequency-tuneable DVA that can modulate its stiffness provides adaptability
to the vibration control device against non-stationary disturbances. Several studies have been
reported in this regard [2–5] but the implementation of such adaptability would be complex and
the response time may become a design issue.
Komatsuzaki et al. [6] and Liao et al. [7] have developed an MRE-based vibration isolator
where real-time semi-active vibration control techniques are applied in order to reduce
vibration in the structure or the payload. Previously published studies also include development
of the adaptive absorbers using MREs. Deng and Gong [8] have proposed a tuneable dynamic
absorber using MRE where a natural frequency shift of 155% could be obtained when a
magnetic field of 1 T was applied that consequently damped the beam vibration effectively.
Lerner and Cunefare [9] have studied MRE-based vibration absorbers in which MREs are
deformed under three different configurations. They have found the configuration and the iron
concentration of MREs that maximize the natural frequency shift of the absorber. While
extending the frequency shift property of the absorber, possible influences on the damper
performance of the ratio of the primary and the adjacent masses, the tuneable range
modulations, and the damping property of the material itself have not yet been elucidated.
Furthermore, these prior studies have been completed under a harmonic disturbance condition
that is less likely to be observed in real applications such as the transient vibration in vehicles.
On this issue, Hoang et al. [10] have analytically investigated the real-time control of transient
vibration in vehicular power trains using an MRE-based, adaptively tuned dynamic absorber;
however, the implementation of such a scheme to the actual equipment has not been realized
thus far.
In this paper, an effective design of the adaptively tuned dynamic absorber is shown against the
target structure in order to maximize the performance of the absorber with a frequency-
tuneable feature. The performance of the proposed MRE-based DVA is evaluated by
comparison to a passive-type absorber with fixed properties. Additionally, the study aims to
show numerically as well as experimentally that the real-time adaptive control is quite possible
for a transient vibration caused by excitation, whose frequency changes with time. Field-
dependent properties of the fabricated MREs are first shown. The MREs are then introduced
into a DVA whose frequency adjustability is evaluated. Finally, the real-time vibration control
performance of the frequency-tuneable absorber for a base-excited, one-degree-of-freedom
system is evaluated. Investigations show that the vibration of the structure can be effectively
reduced with an improved performance by the DVA in comparison to the conventional passive-
type absorber.
2.1 Study

From the very beginning, the theory of vibration absorption was based on two pillars; heavy
damping and frequency separation. Unfortunately nobody paid attention that heavy damping
was a sort of a strong connection between substrate and superstructure and that the idea of
decoupling with the help of such connections was no good.
In the past, early 1800’s passive techniques were used to dampen or absorb the vibrations.
These included traditional vibration dampers, shock absorber sand base isolation. Later it was
observed that these heavy dampers had side effects on the work space or machineries. A tuned
mass damper (TMD) or absorber (TMA), device consisting of a mass, a spring and damper that
is attached to a structure in order to reduce the dynamic response of the structure was
introduced.
The TMA concept was first applied by Frahm IN 1909 (Frahm, 1909) to reduce the rolling
motion of ships as well as ship null vibrations. A theory for the TMA was presented later in the
paper by Ormondroyd and Den Hartog (1928) followed by a detailed discussion of optimal
turning and damping parameters in Hartog’s book on mechanical vibrations (1940). The initial
theory was applicable for an undamped 5DOF system subjected to a sinusoidal force
excitation. Extension of the theory to damped 5DOF systems have been investigated by
numerous researchers. Significant contributions were made by Randalietal (1981), Warburton
(1981, 1982), Warburton and Ayorinde (1980), and Tsai and Lin (1993).
Along the side, based on the publication of Hermann Frahm (1911) invented the dynamic
vibration absorber has been successfully used to suppress wind-induced vibration and seismic
response in buildings. This was followed and characteristics of DVA were studied in depth by
Den Hartog(1985).
During the research and study of the vibration absorbers, we understood that vibrations are the
greatest enemy of the machines in the era of precision manufacturing, but the greatest
disadvantage in using DVA and TMA or TMD were that, these instruments were not able to
suppress the vibrations to greater period and were not able to tune accordingly to the
continuously varying vibration frequencies in the present era world is leading with
technologies of microcontrollers and artificial intelligence. This lead us to think and enact to
try a small experimental project on using active systems and do a adaptively tuned dynamic
vibration absorber system which can tune to any vibration frequencies generated by machine
and dampen/absorb it.
Chapter 3
THEORY BEHIND TUNING OF VIBRATION
In some situation, one DOF (degree of freedom) or multi DOF system may encounter to the
resonance (the excitation frequency nearly coincides with the natural frequency of the system)
with large amplitude of vibration struggling with high dynamic stresses and noise and fatigue

problem. Excessive vibrations in engineering systems are generally undesirable and therefore
must be avoided for the sake of safety and comfort. If neither the excitation frequency nor the
natural frequency can conveniently be altered, this resonance condition can often be
successfully controlled. It is possible to reduce the undesirable vibrations by extracting the
energy that causes these vibrations. The extraction of this energy can be established by
attaching to the main vibrating system a dynamic vibration absorber, which is simply a spring-
mass system. The dynamic vibration absorber is designed such that the natural frequencies of
the resulting system are away from the excitation frequency.
When we attach an auxiliary mass m2 to a machine of mass m1 through a spring with stiffness
k2, two degrees of freedom system will create (Figure 3(a)). The equations of motion of the
masses m1 and m2 are :
(1)
By assuming a harmonic solution,
(2)
We can obtain the steady-state amplitude of the masses m1 and m2 as we can obtain:
(3)
(4)
Figure 3(a): Two degrees of freedom system.
We are primarily interested in reducing the amplitude of the machine X1. In order to make the
amplitude of m1 zero, the numerator of Eq. (3) should be set equal to zero. This gives:
(5)
If the machine, before the addition of the dynamic vibration absorber, operates near its

resonance, .Thus if the absorber is designed such that
(6)
The amplitude of vibration of the machine, while operating at its original resonant frequency,
will be zero. By defining:
(7)
As the natural frequency of the machine or main system, and
(8)
As the natural frequency of the absorber or auxiliary system, equations (3) and (4) can be
rewritten as:
(9)
and
(10)
The variation of the amplitude of vibration of the machine with the machine speed is
observable (Figure 3). The two peaks correspond to the two natural frequencies of the
composite system. As seen before, X1 = 0 at, . At this frequency, equation (9) gives:
(11)
This shows that the force exerted by the auxiliary spring is opposite to the impressed force (
) and neutralizes it, thus reducing X1 to zero. The size of the dynamic vibration
absorber can be found from equations (10) and (6):
(12)
Thus the values of k2 and m2 depend on the allowable value of X2. It can be seen from Figure 3
that the dynamic vibration absorber, while eliminating vibration at the known impressed
frequency introduces two resonant frequencies Ω1 and Ω2 at which the amplitude of the
machine is infinite. In practice, the operating frequency ω must therefore be kept away from
the frequencies Ω1 and Ω2.

Figure 3(b): Effect of the dynamic vibration absorber on the response of machine
3.1 Governing Equations for Base Structure
The governing equation for the natural frequency of a simply supported beam is given by
(Thomson, 1997)
(13)
For the rectangular uniform beam, E = 207 Pa, ρ= 7800 .
The second moment of inertia, I = ( )/12.
The value (ρl)2
depends on the boundary conditions of the beam. For the simply supported
beam, (ρl)2
is 9.87 (for the fundamental mode).
For a beam, b = 0.025m, h = 0.012m, l = 0.85m
(14)
3.2 Governing Equations for Cantilevered Absorber Using Discrete System
Method
The absorber system is assumed to be composed of discrete systems. The absorber mass at the
end of the rod is assumed to be one system, and the rod itself is another. If the damping present
in the system is neglected, Dunkerleys equation (Ramamurti, 2000) can be used for analysis.
For the natural frequency, of a cantilevered beam of mass, m1,
(15)
For the absorber device, two rods are in parallel, with the mass attached at L=0.1.
The total stiffness produced by the 2 rods in parallel is,
kt = k1 + k2
(16)
For the natural frequency, of a cantilevered beam of negligible mass with a concentrated

mass attached at one end,
(17)
Using Dunkerleys equation,
(18)
3.3 Expected Result
Figure 3.3: Model of Adaptive tuned dynamic vibration absorber
with the slider-crank mechanism
In this project we presented a new smart device which can adjust itself into the best optimum
situation by the slider crank mechanism very quickly. So, it would absorb the unexpected
vibrations fast and accurately.
From figure 1 it can be seen that the adaptive tuned dynamic vibration absorber has been
clamped below the motor and converted the one degree of freedom system into the two degree
of freedom system. It comprises two bodies of equal mass fixed equidistant from the midpoint
of the horizontal cantilever and they move backward and forward together with the use of a
servo motor and two slider-crank mechanisms. The distance apart of the bodies varies until the
system is tuned (Figure 3.3).
3.4 Different Sections of the System
Our device has different parts which include main beam, motor with rotary disc and adaptive
tuned dynamic vibration absorber system as shown below.
3.4.1 Motor with Rotary Disc above beam

Figure 3.4.1: Motor with rotary disc and Speed controller.
The motor is connected to a speed control through which the speed of rotation can be varied
(Figure 5).The first part which is beam, has been fixed between two joints, one of them is fixed
joint another one is roller joint. Actually the theory is applied to a simply supported beam
carrying a motor with mass unbalance at its mid-span as shown in figure 1. The motor is
connected to a speed control through which the speed of rotation can be varied.
3.4.2 Speed Control Unit and Exciter Motor
Figure 3.5.1 shows the speed control unit that is used in this experiment. A DC motor is used
for all forced vibrations experiments powered by a control unit. This combination comprises of
a control box and DC motor, which provides high precision speed control of the motor up to
3000 rev/min, irrespective of the normal load fluctuations of the motor.
3.4.3 Rotary Disc
Vibration force is applied by the rotation of perforated rotary disk. With the various speed of
the motor, vibration force which is applied to system is different.
3.4.4 Slider-Crank Mechanism
As we mentioned before, two bodies of equal mass move backward and forward together with
the use two slider-crank mechanisms. In this section, we examine the slider crank mechanism.
3.4.5 Kinematics of the Slider-Crank Mechanism (Kearney, 2005)
Figure 3.4.5: Slider-crank mechanism.
The slider crank mechanism, (Figure 3.4.5) is a kinematic mechanism. The piston (sliding
block) displacement x, can be determined from the geometry of the mechanism. In this project,

we designed slider-crank mechanism as a result of comprehensive concepts of Freudenstein's
equation which has been shown below.
(20)
According to this equation we have designed a mechanism with these specifications Lengths<:
L2=8, L3=10.5, L4=0
3.5 Electronic Section
3.5.1 Electronic Section's Duty
Function of the electronic parts can be summarized into the following two cases:
i. Measuring the rate of vibration
ii. The rotation of actuator
In this part we will install an accelerometer on the supported beam for measuring the rate of
vibrations, despite of this fact we used a diversion measurement system. So with a 3-Axis
Accelerometer sensor we would measure the rate of vibration and if it was unacceptable, the
servo motor will rotate and would change position of masses to damping the vibrations. If the
change was enough, the actuator would stop but if not, the distance between masses would
change until the optimize situation.
3.5.2 Calibration
Figure 3.5.2: Location of control keys on the electronic circuit.
In this scheme, we have setup calibration system in order to adjust our device on various
machines. So, two control keys have been setup on the circuit for adjusting the limitation of the
accelerometer range between 1 and 8. For instance, in this system, we adjusted it on the range
of 2. So if the acceleration in each direction becomes greater than 2, the system will begin to
adapt.
Also, In order to monitor the rate of acceleration in a steady situation, a control button has
been placed (Figure 3.5.4.2).
3.5.3 Arduino Board
An Arduino board is a one type of microcontroller-based kit. The first Arduino technology

was developed in the year 2005 by David Cuartillas and Massimo Banzi. The designers
thought to provide easy and low-cost board for students, hobbyists and professionals to build
devices. Arduino board can be purchased from the seller or directly we can make at home
using various basic components. The best examples of Arduino for beginners and
hobbyists include motor detectors and thermostats, and simple robots. In the year 2011,
Adafruit industries expected that over 3lakhs Arduino boards had been produced. But, 7lakhs
boards were in user’s hands in the year 2013. Arduino technology is used in many operating
devices like communication or controlling.
3.5.3.1 Arduino Pin Diagram
The pin configuration of the Arduino Uno board is shown in the above. It consists of 14-
digital i/o pins. Wherein 6 pins are used as pulse width modulation o/ps and 6 analog i/ps, a
USB connection, a power jack, a 16MHz crystal oscillator, a reset button, and an ICSP
header. Arduino board can be powered either from the personal computer through a USB or
external source like a battery or an adaptor. This board can operate with an external supply of
7-12V by giving voltage reference through the IORef pin or through the pin VIN.
3.5.3.2 Digital I/Ps.
It comprises of 14-digital I/O pins, each pin take up and provides 40mA current. Some of the
pins have special functions like pins 0 & 1, which acts as a transmitter and receiver
respectively. For serial communication, pins-2 & 3 are external interrupts, 3,5,6,9,11 pins
deliver PWM o/p and pin-13 is used to connect LED.
Analog i/ps: It has 6-analog I/O pins, each pin provides a 10 bits resolution.
Aref: This pin gives a reference to the analog i/ps.
Reset: When the pin is low, then it resets the microcontroller.
3.5.3.3 Arduino Architecture
Figure 3.5.3.3: Arduino Architecture
Basically, the processor of the Arduino board uses the Harvard architecture where the
program code and program data have separate memory. It consists of two memories such as
program memory and data memory. Wherein the data is stored in data memory and the code
is stored in the flash program memory. The Atmega328 microcontroller has 32kb of flash

memory, 2kb of SRAM 1kb of EPROM and operates with a 16MHz clock speed.
3.5.3.4 Arduino Program
 Programming into the arduino board is called as sketches. Each sketch contains of
three parts such as Variables Declaration, Initialization and Control code. Where,
Initialization is written in the setup function and Control code is written in the loop
function.
 The sketch is saved within and any operation like opening a sketch, verifying and
saving can be done using the tool menu.
 The sketch must be stored in the sketchbook directory.
 Select the suitable board from the serial port numbers and tools menu.
 Select the tools menu and click on the upload button, then the boot loader uploads the
code on the microcontroller
3.5.3.5 Basic Functions of Arduino Technology
 Digital read pin reads the digital value of the given pin.
 Digital write pin is used to write the digital value of the given pin.
 Pin mode pin is used to set the pin to I/O mode.
 Analog read pin reads and returns the value.
 Analog write pin writes the value of the pin.
 Serial. Begins pin sets the beginning of serial communication by setting the rate of bit.
3.5.3.6 Advantages of Arduino Technology
 It is cheap.
 It comes with an open supply hardware feature that permits users to develop their own
kit.
 The software of the Arduino is well-suited with all kinds of in operation systems
like Linux, Windows, and Macintosh, etc.
 It also comes with open supply software system feature that permits tough software
system developers to use the Arduino code to merge with the prevailing
programming language libraries and may be extended and changed.
 For beginners, it is very simple to use.
3.5.3.7 L293D IC Motor Driver
An L293D is an integrated chip which is used to control motors in autonomous Robots and
also in Embedded Circuits. L293D and L29NE are the most commonly used motor driver IC,
these are designed to control two motors simultaneously. L293D has a dual H-Bridge

Figure 3.5.3.7: Pin diagram of L293D IC
motor Driver integrated circuit. This motor driver acts as a current amplifier. The motor takes
a low-signal current and provides a high-output signal at Output. This high signal current is
then transferred to the attached Motor.
We can also build H-Bridge in these motors, which can be built from scratch with the help of
a Bi-polar junction Transistor (BJT) or with a Field Effect Transistor (FET). For the low
current profile, L293 is simple and inexpensive for low current motors and it becomes
Expensive. The L293 is limited to s but in reality, it is limited to much smaller current than
this. Exceeding temperature in L293 would increase its temperature so; we should have to do
some serious heat sinking in it to make it usable.
3.5.3.8 Tmega 328
Figure 3.5.3.8: AT mega 328
The ATmega328 is a single-chip microcontroller created by Atmel in the mega AVR family.
It has a modified Harvard architecture 8-bit RISC processor core. The Atmel 8-bit AVR
RISC-based microcontroller combines 32 kB ISP flash memory with read-while-write
capabilities, 1 kB EEPROM, 2 kB SRAM, 23 general purpose I/O lines, 32 general purpose
working registers, three flexible timer/counters with compare modes, internal and external
interrupts, serial programmable USART, a byte-oriented 2-wire serial interface, SPI serial
port, 6-channel 10-bit A/D converter (8-channels in TQFP and QFN/MLF packages),
programmable watchdog timer with internal oscillator, and five software selectable power
saving modes. The device operates between 1.8-5.5 volts. The device achieves throughput
approaching 1 MIPS per MHz.

Chapter 4
VIBRATION ABSORBERS
The vibration absorber, also called dynamic vibration absorber, is mechanical device used to
reduce or eliminate unwanted vibration. It consists of another mass and stiffness attached to the
main (or original) mass that needs to be protected from vibration. Thus the main mass and the
attached absorber mass constitute a two-degree-of-freedom system, hence the vibration
absorber will have two natural frequencies. The vibration absorber is commonly used in
machinery that operates at constant speed, because the vibration absorber is tuned to one
particular frequency and is effective only over a narrow band of frequencies. Common
applications of the vibration absorber include reciprocating tools, such as sanders, saws, and
compactors, and large reciprocating internal combustion engines which run at constant speed
(for minimum fuel consumption). In these systems, the vibration absorber helps balance the
reciprocating forces. Without a vibration absorber, the unbalanced reciprocating forces might
make the device impossible to hold or control.
4.1 Dynamic Vibration Absorbers
Figure 4.1: vibration absorber
A sinusoidal force F0sin wt acts on an undamped main mass-spring system (without the
absorber mass attached). When the forcing frequency equals the natural frequency of the main
mass the response is infinite. This is called resonance, and it can cause severe problems for
vibrating systems.
When an absorbing mass-spring system is attached to the main mass and the resonance of the
absorber is tuned to match that of the main mass, the motion of the main mass is reduced to
zero at its resonance frequency. Thus, the energy of the main mass is apparently "absorbed" by
the tuned dynamic absorber. It is interesting to note that the motion of the absorber is finite at
this resonance frequency, even though there is NO damping in either oscillator. This is because
the system has changed from a 1-DOF system to a 2-DOF system and now has two resonance
frequencies, neither of which equals the original resonance frequency of the main mass (and
also the absorber).

If no damping is present, the response of the 2-DOF system is infinite at these new frequencies.
While this may not be a problem when the machine is running at its natural frequency, an
infinite response can cause problems during startup and shutdown. A finite amount of damping
for both masses will prevent the motion of either mass from becoming infinite at either of the
new resonance frequencies. However if damping is present in either mass-spring element, the
response of the main mass will no longer be zero at the target frequency.
4.2 Vibration Measuring Instruments
These are the instruments which are used to measure the vibration and analyze the frequencies
of vibrations. Depending on the quantity to be measured, a vibration measuring instrument is
called a vibrometer, accelerometer, a phase meter, a velocity meter, or a frequency meter.
In this project we are using accelerometer. Hence lets concern only about accelerometer for
time being.
4.3 Accelerometer
Figure 4.3: Accelerometer
An accelerometer is an instrument that measures the acceleration of a vibrating body.
Accelerometers are widely used for vibration measurements and also to record earthquakes. An
accelerometer behaves as a damped mass on a spring. When the accelerometer experiences
acceleration, the mass is displaced and the displacement is then measured to give the
acceleration.
The principle of working of an accelerometer can be explained by a simple mass (m) attached
to a spring of stiffness (k) that in turn is attached to a casing, as illustrated in fig 2.1. The mass
used in accelerometers is often called the seismic-mass or proof-mass. In most cases the system
also includes a dashpot to provide desirable damping effect.
4.4 Adaptive Tuned Dynamic Vibration Absorber

Figure 4.4: Model of Adaptive Tuned Dynamic Vibration Absorber
When the structure is undergoing vibration usually dynamic vibration absorbers are used. So
there is need to tune the vibration absorber frequency in case of repeatedly changing vibration
cycles. Here the solution is to use adaptive tuning dynamic vibration absorbers which can tune
its vibration frequency to that of source vibration frequencies.
When a structure is undergoing some form of vibration, there are a number of ways in which
this vibration can be controlled. Two general types of external dampers may be added to a
mechanical system in order to improve its energy dissipation characteristics. They are:
1. Passive control
2. Active control
Passive control involves some form of structural augmentation or redesign, often including the
use of springs and dampers that leads to a reduction in the vibration. Active control augments
the structure with sensors, actuators and some form of electronic control system, which
specifically aim to reduce the measured vibration levels.
Over the last decade, smart devices have been studied as potential alternatives to the use of
conventional control mechanisms for controlling mechanical vibrations. This research
investigates the use of Adaptive Tuned Dynamic Vibration Absorbers (ATDVA) with smart
slider-crank mechanism to control vibration in a structure.
This study proposes a new design with the use of smart slider crank mechanism. Our purpose
in this scheme is to enhance the accuracy and speed, to control of undesirable vibrations. A
dynamic vibration absorber is essentially a secondary mass, attached to an original system via a
spring and damper. The natural frequency of the DVA is tuned such that it coincides with the
frequency of undesirable vibrations in the original system.
Chapter 5

PROJECT METHODOLOGY
5.1 Introduction:
This chapter will cover the detail explanation of methodology that is being to make this
project complete and working and working well. Many methodology or findings from this
field mainly generated into journal for others to take advantages and improve as upcoming
studies. The method is use to achieve the objective of the project that will accomplish a
perfect result, generally three major steps, which is planning, implementation and analysis.
i. Planning
a) Data collection
b) Hardware and software requirements
ii. Implementation
a) Fabrication
5.2 Planning
To identify all the information and requirement such as hardware and software, planning must
be done in the proper manner. The planning phase has two main elements namely data
collection and the requirements of hardware and software.
5.2.1 Data collection
Data collection is a stage in any area of study. At this stage we planned about the project’s
resources and requirements, literature studies and schedule to get more information in this
study, all the materials are collected from journal, texts book and research papers gathered
from libraries and internet.
Within the data collection period we have found the study about crop cutter in the internet
and did some research about the project related. Once we got the project manual, we tried to
find out the electronics component and other materials and some of equipment to be used.
While planning, we had done research about the project related , which including with
study about the mechanical component such as dc motors, microcontrollers, RF receivers
and transmitters and other components. The study is not just for function of the component
but also its suitability to our project.
5.2.2 Software requirement
 Arduino software
 CATIA V5
 ANSYS
 Hypermesh
5.2.3 Hardware requirement
 Frame Metals, MS
 Clamps

 Mild steel bar
 Spring
 Servo motor, MG665
 Arduino microcontroller unit
 Bread circuit
 DC Battery
 AC Motor
 AC Power supply
5.2.4 Specification of component
 Frame width 1000mm
 Frame height 800mm
 Metal bar length 800mm
 AC motor speed 1450 rpm
5.3 Implementation
5.3.1 Construction
Figure 5.3.1(a): Fabrication of Frame
 The primary task for us was the fabrication of frame and installation of MS bar as a
cantilever beam. The clamps were designed to fix the bar on one side of the frame and
the other end is joined to the end of suspended spring so than it will vibrate as desired
when the excitation frequency is provided.
 The assembly of controlling unit that consisted of Arduino microcontroller, motor drive,
servo motor, slider-crank mechanism, accelerometer and power supply is completed by
the correct circuit design as shown in Figure 6.3.1(b).

Figure 5.5.1(b): Circuit design for controlling of servomotor using the accelerometer
 We have been ready with the frame of the setup with proper arc welding. It has the exact
dimension of 1000*800mm as per the design. The metallic bar is ready to be set up as a
cantilever beam on the vertical wall of the frame with the aid of clamp. The electric
materials such as AC motor and dimmer stat are ready and electronic materials are also
collected.
 The cantilever beam is yet to be clamped on the frame. The AC motor, eccentric mass on
it, servo motor, two ways cantilever beams are yet to be clamped on the main beam. The
spring is to be added on the other end of the main beam. The two masses have to be
prepared manually as per the design requirement. All of these works has to be done in the
workshops with the proper use of tools, jig and fixtures.
Chapter 6
DESIGN, ANALYSIS AND EXPERIMENTATION

6.1 Materials Required
The components used in Adaptive tuned dynamic vibration absorbers are as follows
i. Rectangular frame
A rectangular frame is made for the foundation and constructing the model.
Table i: Material dimension
Material Mild steel
Width 1000mm
Height 800mm
Thickness 4mm
ii. Cantilever beam
Cantilever beam is the structure, which is taken here for conducting analysis of ADTVA.
Cantilever beam is a flat bar which is fixed to the rectangular frame which is made up of mild
steel and 5mm thick and 800mm long.
iii. Clamps
Right angled Clamps are used to fix the cantilever beam to the rectangular frame which is
undergoing vibrations.
Table iii: Clamps
Material Mild steel
Length 50mm
Width 50mm
Height 50mm
Thickness 10mm
iv. AC Motor
AC motor is used as vibration source. AC motor with suitable eccentric mass creates the
vibration and transfers it to the cantilever beam.
The description of AC Motor is as follows:
Table iv: AC motor
Voltage 250V
Frequency 50Hz
Phase Single
Amperes 1:10
HP 1/5
Watts 149
RPM 1450
v. Eccentric mass
A circular disc made up of iron is used as eccentric mass which is to be mounted on the shaft of
the AC Motor to induce the vibration in the experimental setup/model.

Table v: Eccentric mass
Material Steel*
Diameter 200mm*
Thickness 10mm*
Mass 750grams*
*currently used in software analysis later when subjected to experimental setup analysis may vary
accordingly.
vi. Spring
A spring of length 340mm* is used at the end of cantilever beam which is supported to the
rectangular frame vertically. Spring is used for restricting the degree of freedom of the
vibration induced in the cantilever beam.
accordingly.
vii. Cantilever beam for secondary masses.
Cantilevered beams are fixed on the top of the AC motor which carries adjustable secondary
masses for absorbing vibrations.
Table vii: cantilever beam for secondary mass
Length 170mm
Width 15mm
Material Stainless steel
Total No. of quantity 2 Nos.
viii. Secondary masses
Secondary masses is used as vibration absorbing system. These are the cubical structure which
are connected to end of slider crank system.
Table viii: Secondary masses
Width 25mm*
Breadth 50mm*
Height 35mm*
Total No. of quantity 4 Nos.
accordingly.
ix. Slider crank links
Slider crank is used to move the secondary masses to the desired position so as to match the
frequency of secondary system to that of source vibration frequency which eventually dampens
the original vibrations.
Table ix: Slider crank links
Connecting rod length 75mm*
Crank rod length 25mm*

accordingly.
x. Servomotor
Servomotor is connected to the slider crank mechanism which moves the secondary masses.
Servomotor used here is MG995.
Table x: servomotor
Modulation Digital
Torque 4.8V: 130.54 oz-in (9.40 kg-cm)
6.0V: 152.76 oz-in (11.00 kg-cm)
Speed 4.8V: 0.20 sec/60°
6.0V: 0.16 sec/60°
Weight 55 grams
Gear Type Metal
xi. Accelerometer
Accelerometer is used to detect the vibration motion on the cantilever beam. Accelerometer
used here is MPU6050.
Table xi: Acceleromotor
Power supply 3~5V Onboard regulator
Gyroscopes range +/- 250 500 1000 2000 degree/sec.
Acceleration range +/- 2g, +/- 4g, +/- 8g, +/- 16g.
Pin pitch 2.54mm
Communication mode standard IIC communication protocol
xii. Arduino
Figure xii: Arduino UNO
Arduino is used to collect the information from accelerometer and process the data and control
the servomotor. In this project, we are using Arduino UNO which is widely used. An Adriano
board is a one type of microcontroller-based kit. The first Arduino technology was developed
in the year 2005 by David Cuartillas and Massimo Banzi. The best examples of Arduino for
beginners and hobbyists include motor detectors and thermostats, and simple robots. Arduino
technology is used in many operating devices like communication or controlling.

xiii. Dimmer-stat and Tachometer
Dimmer stat is used to control the voltage input to the AC motor and hence control the rpm.
Whereas tachometer is used to measure the rpm of the AC motor.
xiv. Batteries and power cables
Batteries are used to power up the electric components used through the power cables. A Li-Po
battery of 11.1V with 2200mAh is used for the operation of Arduino and accelerometer
circuits.
6.2 3D-CAD Modeling
Figure 6.2(a):The assembled 3D model Figure 6.2(b): Front View
The CAD modeling has been done with the help of CATIA V5R20. The dimensions and
specifications are shown in the drawing in the Figure 5.2(c). Above are the images and details
of the assembled 3D model.
The frame is made up of steel with dimension 1000mm*800mm, where it has cross sectional
width and length 80mm*40mm*3.5mm as its dimension. The cantilever which holds the entire
setup is again steel of 800mm length and 5mm thickness. The spring which is about 350mm in
length with a minor expansion due to its elongation as its original length is 320mm without
considering the hook. The AC motor which is mounted on the cantilever beam is of mass
2.5Kg giving out 1400rpmits controlled by a dimmer stat. The Eccentric mass which is in
circular shape mounted on the shaft of the Ac motor is of 200mm in Diameter and 15mm in
thickness it has hole in it as shown to switch its CG as rotating generates an imbalance thereby
leading to vibration in the system. Below is the Draft of the frame.

Figure 6.2(c): drawing of assembly (drafting)
Now we see there will be vibration generated to balance this we are introducing a system as
shown below which a combination of servo motor is controlled by arduino board with help of
accelerometer sensor, cantilever beam, mass, slider crank mechanism as shown. We are unable
to see the balancing mass in draft as it can be changed depending on the motor and its rpm, also
owing further future changes its not shown ion draft. But it’s shown how it is placed in the 3D
model for representation with respect to current dimension and materials procured. Below is
the image of the damper system. The electric connection is not shown in the 3D model .But
shown in for coming.
Figure 6.2(d): servomotor and cantilever beam assembly
6.3 Analysis

Figure 6.3(a): Structural analysis of cantilever beam
We have done structural analysis with the aid of Hypermesh and Ansys APDL for better
quality of mesh and approximate result. Following are the details that indicate the analysis
conducted on the cantilever beam which holds the entire setup.
This gives the result that it can withstand stress upto22061Mpa. The blue line here indicates the
spring and its action. Also when conduct a modal and harmonic test its gives its frequency
beginning with 3.82Hz and goes on with a progression up to 28.281Hz (note this was
conducted only for 1st
6 harmonic). Further tests are to be done and as we have to fabricate and
then only perform them few trial and error and give further results.
Figure 6.3(b): Analysis of rotary disc/eccentric mass
6.3.1 Analysis Results based on the Journal

Figure 6.3.1(a): Model in visualization.
In order to analyse the whole device with more accuracy and for predicting various conditions
of the device, Adaptive Tuned Dynamic Vibration Absorber has been simulated by finite
element method (Segerlind, 1984) with ABAQUS. So the whole model has been designed into
the part section and has given the same property as it was in a real situation. Then the whole
model has been assembled and has given the suitable interactions. At the next step, the
assembled model were partitioned and meshed by the most suitable technique which is called
structured and 6368 elements have been generated on this model with quadratic geometric
order (Figure 6.3.1(a)). Into the next step, the same amplitude which has been shown in the
next part is going to incur on the top-middle of the whole model.
Figure 6.3.1(b): Analysis of the rotary disc
The rotary disc which is causes of undesirable vibrations has been simulated. Therefore the
reaction force in direction 2 (Y-axis) on the central node of the disc has been plotted. The
results from the plot are going to define the amplitude of concentrated force which is incur on
the top-middle of simply supported beam instead of rotary disc in simulation (Figure 6.3.1(b)).

Figure 6.3.1(c): Analysis of rotary disc and reaction forces.
The results are going to show the acceleration of one specific node during the load with
dynamic vibration absorber or without (Figure 6.3.1(e)).
Figure 63.1(d): Analysis of the Cantilever bar
Figure 6.3.1(e): Acceleration differences- results with linear perturbations (Tosio Kato, 1995).
So, it can be proven that in a beam without dynamic vibration absorber, the acceleration in Y-
axis on a specific point where we had put an accelerometer on, was considerably more than a
beam with dynamic vibration absorber.

6.4 Experimental Results based on the Journal
Figure 6.4: Comparison of different methods to control of vibration according to the numerical results during the
experiment.
Adaptive Tuned Dynamic Vibration Absorber (ATDVA) and Dynamic Vibration Absorber
(DVA) has been experimented in the real situation on the simply supported beam in the
laboratory and interestingly the results are almost as same as in comparison with the results of
the simulation model. With the compare of diagrams in the following figure, it can be seen
that, ATDVA damped the resonance and it has been decreased the rate of vibration on the
device in every forces acting which is applied by changing the speed of motor and rotary disk
on the machine during the experiment. According to the resulting values, we provide a diagram
for each method (Figure 6.4). But with the DVA, The primary system possess to the
characteristics of a two-degrees of freedom (Hunt, 1979) which it has two natural
frequenciesΩ1 and Ω2 (Korenev et al., 1993). So whenever the dynamic absorber is tuned to
one excitation frequency , the steady-state amplitude of the machine is zero only at that
frequency. If the machine operates at other frequencies or if the force acting on the machine
has several frequencies, then the amplitude of vibration of the machine may become large
(Nishimura et al., 1990).

Chapter 7
SUMMARY
7.1 Conclusion
The aim of this device is to reducing the undesirable vibrations by a smart and adjustable
system. Our findings suggest that a dynamic vibration absorber, which includes adjustable
mechanism and control circuits that are completely manageable with many devices, will be
controlled the undesirable vibrations. Despite the fact our design cannot be embedded to the
mechanical devices directly, the following conclusions can be drawn from the present study:
1- Low administrative cost compared to other methods and mechanisms.
2- Decreasing the rate of vibration on the system, in every forces acting which is applied.
3- This device is affordable and suitable in many industrial places and laboratories.
Therefore, in this method, we eliminated some problems of the currently existing method,
though this method can be developed for the future. Further research might explore different
mechanisms and different options for dynamic vibration absorber. We hope the results of this
study can be used for better promoting of this method.
7.2 Scope for Future
 The system can be embedded in the mechanical devices and systems.
 The design can be modified according to need of mechanical devices.
 With the advancement of technology, the mechanical components can be reduced to a
higher extent which will reduce the space requirement as well as the cost.
 It can be used in all kinds of mechanical devices like motors, pumps, compressors etc.
 It can be employed in all sectors of the industrial equipment and machineries.
 Further development can be done to practice its application in vehicles too.

REFERENCES
[1] S. Graham Kelly: “Fundamentals of Mechanical Vibrations”, Schaum’s outline Series, Tata
McGraw Hill, Special Indian Edition, 2007, page 247-452
[2] S. S. Rao : “Mechanical Vibrations”, Pearson Education Inc., 4th
edition, 2003, Page 290-
446
[3] Den, H. (1985). "Mechanical Vibrations" Published By McGraw-Hill, New York,
pages:87-106
[4] Denys, J. M. (1999). "Passive Vibration Control" Wiley, 1-31
[5] Hunt, J. B. (1979). "Dynamic Vibration Absorbers Mechanical Engineering" Publications
Ltd London
[6] Kearney M. (2005). Laboratory Sheet, Kinematics of a slider-crank mechanism
[7] Nishimura, H., Yoshida, K., Shimogo, T. (1990), "Optimal Active Dynamic Vibration
[8] Absorber for Multi-Degree-of-Freedom Systems", JSME International Journal, Vol. 33,
[9] Ramamurti, V. (2000). "Mechanical Vibration Practice With Basic Theory"
[10] Samali, B., Al-Dawod, M., Naghdy, F. (2004). "Active Control of Cross Wind Response
of 76-Story Tall Building Using a Fuzzy Controller", Journal of Engineering Mechanics
[11] Thomson, T. (1997). "Theory of Vibration with Applications"
[12] Timoshenko, D. H. Young, W. (1974). "Vibration Problems in Engineering" John Wiley
[13]Tosio Kato. (1995)."Perturbation Theory for Linear Operators (Classics in Mathematics)"
Springer.

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