TYPES OF VIBRATION

1. SUBMITTED BY:
NAME:-SHASHI RANJAN
AD. NO.:- 19GPTC4010009
TYPES OF VIBRATIONS
CAT-III

2. INTRODUCTION
What is Vibration Definition?
Vibration defined as when an elastic body such as spring, a beam, and a shaft are displaced
from the equilibrium piston by the application of external forces and then released they
executive as vibratory motion.
For better understanding, When body particles are displaced by the application of external
force, the internal force in the form of elastic energy are present in the body, tries to bring
the body to its original position.
At equilibrium position, the whole elastic energy is converted into kinetic energy and the
body continues to move in the opposite direction of it.
The whole of kinetic energy is again converted into elastic or strain energy due to which the
body again returns to its equilibrium position.
In this way, vibratory motion is repeated indefinitely and exchange of energy takes place.
Thus, any motion which repeats itself affect an interval time is called Vibration or
Oscillation.

3. VIBRATION TYPES
There are 3 types of Vibration:
1.Free or Natural
2.Forced
3.Damped Vibration

4. VIBRATION TYPES
Free vibration:
Free vibration occurs when a mechanical system is set in motion with an initial input and
allowed to vibrate freely. Examples of this type of vibration are pulling a child back on a
swing and letting it go, or hitting a tuning fork and letting it ring. The mechanical system
vibrates at one or more of its natural frequencies and damps down to motionlessness.

5. VIBRATION TYPES
Forced vibration :
Forced vibration is when a time-varying disturbance (load, displacement, velocity, or
acceleration) is applied to a mechanical system. The disturbance can be a periodic and
steady-state input, a transient input, or a random input. The periodic input can be a
harmonic or a non-harmonic disturbance. Examples of these types of vibration include a
washing machine shaking due to an imbalance, transportation vibration caused by an
engine or uneven road, or the vibration of a building during an earthquake. For linear
systems, the frequency of the steady-state vibration response resulting from the application
of a periodic, harmonic input is equal to the frequency of the applied force or motion, with
the response magnitude being dependent on the actual mechanical system.

6. VIBRATION TYPES
DAMPED VIBRATION:
When the energy of a vibrating system is gradually dissipated by friction and other
resistances, the vibrations are said to be damped. The vibrations gradually reduce or
change in frequency or intensity or cease and the system rests in its equilibrium position.
An example of this type of vibration is the vehicular suspension dampened by the shock
absorber.

7. TYPES OF FREE VIBRATION
Types of Free Vibration:
1.Longitudinal
2.Transverse and
3.Torsional Vibration.

8. TYPES OF FREE VIBRATION

9. VIBRATION TYPES
Longitudinal:
In this, the particles of the shaft or disc move parallel to the axis of the shaft as shown in the above diagram.
In this case, the shaft is elongated and shortened alternately thus executing the tensile and compressive stresses
alternately on the shaft.
Transverse vibrations:
In this, the particles of the shaft or disc move perpendicular to the axis of the shaft as shown in the above diagram.
Here the shaft is straight and bent alternatively and hence bending stresses are induced in the shaft.
Torsional Vibrations:
In this, the particles of the shaft or disc move in a circle about axis of the shaft as shown in the above diagram.
Here the shaft is twisted and untwisted alternatively and hence torsional shear stress is induced in the shaft.