Mechanics of Machines & Vibrations
Dr Farid Khan
Dr. Farid Khan
Assistant Professor in UET Peshawar since 1997
B.Sc Mechanical Engineering 1997
M.Sc Mechanical Engineering Design 2005
PhD MicroEle
Mechanics of Machines & Vibrations
Lecture: 17
Dr Farid Khan
MDOF systems
2
MDOF systems
3
MDOF systems
4
MDOF systems
5
MDOF systems
6
MDOF systems
7
MDOF systems
8
MDOF systems
9
MDOF systems
10
MDO
Mechanics of Machines & Vibrations
Lecture: 18
Dr Farid Khan
MDOF systems
2
MDOF systems
3
MDOF systems
4
MDOF systems
5
MDOF systems
6
MDOF systems
7
MDOF systems
8
MDOF systems
9
MDOF systems
10
MDO
Mechanics of Machines & Vibrations
Lecture: 19
Dr Farid Khan
MDOF systems
2
MDOF systems
3
MDOF systems
4
MDOF systems
5
MDOF systems
6
MDOF systems
7
MDOF systems
8
Example: Compute the force transmi
Mechanics of Machines & Vibrations
Lecture: 21
Dr Farid Khan
Gear type
Worm gears:
A worm gear is a gear set in which a worm resembles a screw, while
the other is like a normal spur/helical wheel
Tran
Mechanics of Machines & Vibrations
Lecture: 20
Dr Farid Khan
Gear
?
2
Gear
A circular disc/wheel with a specially designed teeth
Used to transmit power (Power transmission element)
Gears are toothe
Mechanics of Machines & Vibrations
Lecture: 22
Dr Farid Khan
Gear train
2
Gear train
3
Internal gear train
Speed of driver gear t eeth on driven gear
GR
Speed of driven gear t eeth on driver gear
4
E
Mechanics of Machines & Vibrations
Lecture: 23
Dr Farid Khan
Cam
?
2
Cam
A Cam is a machine component that either rotates or moves back
and forth (reciprocates) to create a prescribed motion in a
con
Mechanics of Machines & Vibrations
Lecture: 14
Dr Farid Khan
SDOF forced vibrations
2
SDOF forced vibrations
Base excitation
3
Base excitation
4
Base excitation
5
Base excitation
6
Base excitation
7
B
Mechanics of Machines & Vibrations
Lecture: 12
Dr Farid Khan
SDOF forced vibrations
Force of excitation is always acting on the system during vibrations
The system will vibrate at the frequency of e
Mechanics of Machines & Vibrations
Dr Farid Khan
Review slide
2
Review slide
Classification of vibration
3
Review slide
4
Classification of vibration
5
Classification of vibration
6
Classification of
Mechanics of Machines & Vibrations
Dr Farid Khan
Vibration analysis procedure
2
Free/Natural vibrations
Natural frequency
Or
Undamped natural frequency
n
k
m
3
Free/Natural vibrations
How ?
n
k
m
4
Mechanics of Machines & Vibrations
Lecture: 6
Dr Farid Khan
Harmonic motion
Newtons law
m kx 0
x
Other forms of solutions
k
m
x
2
Harmonic motion
Newtons law
m kx 0
x
3
Some useful quantities
4
Peak v
Mechanics of Machines & Vibrations
Dr Farid Khan
Equation of motion
Newtons law
m
x
F
k
m
m kx
x
m kx 0
x
x
n
k
m
x(0) x0
x(0) v0
2
Equation of motion
Newtons law
m
x
k
F
m
m kx
x
x
m kx 0
x
x(0) x
Mechanics of Machines & Vibrations
Lecture: 9
Dr Farid Khan
Problem
2
Problem
3
Problem
4
Problem
T I
5
Problem
6
Problem
7
Problem
8
Problem
9
Assignment
10
Mini projects
1. Demonstration model of Sp
Mechanics of Machines & Vibrations
Lecture: 10
Dr Farid Khan
Problem 1
Solution:
2
Problem 1
. 1
. 2
. 3
rad/s
<1
3
Problem 1
4
Problem 2
5
Problem 2
Solution:
I
T
( above the pivot)
I bz l kzl
mbarl
Mechanics of Machines & Vibrations
Lecture: 11
Dr Farid Khan
Damping ratios, examples
2
Logarithmic decrement
A method to experimentally measure damping ratio in underdamped systems
X
3
Logarithmic d