types of vibration

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 : Free or Natural Forced 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 : Longitudinal Transverse and  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.

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