Frequency Analysis of a rotating shaft

FREQUENCY ANALYSIS ON A ROTATING SHAFT

AIM : To perform frequency analysis on above rotating shaft

OBJECTIVE :

• To create a model of appropriate dimensions in Solidworks as shown above.
• To conduct a frequency analysis and to apply a bearing fixture on the stepped face .
• To perform the analysis on the rotating shaft and find the critical frequencies for the same.

INTRODUCTION :

Vibration is a mechanical phenomenon whereby oscillations occur about an equilibrium . The oscillations may be periodic such as the motion of a pendulum—or random, such as the movement of a tire on a gravel road.

Different types of vibration are :

• Free vibration : Free vibration is a type of vibration in which a force is applied once and the structure or part is allowed to vibrate at its natural frequency.
• Forced Vibartion : Forced Vibration is a type of vibration in which a force is repeatedly applied to a mechanical system
• Damped vibration : When the energy of a vibrating system is gradually dissipated by friction and other resistances, the vibrations are said to be damped.

Frequency is the number of vibration that pass a fixed point in a given amount of time. The SI unit for frequency is the Hertz (Hz).

PROCEDURE :

Firstly we modelled the shaft as per suitable dimensions.Then we created a new frequency analysis study .

We then provided the required material and provided the bearing fixture to the stepped face on both the sides.We then created the mesh and ran the study.

RESULTS :

After performing the analysis we are able to observe the following plots for different amplitudes.

Amplitude 1

Amplitude 2

Amplitude 3

Amplitude 4

Amplitude 5

RESULTS	MAX AMPLITUDE	MIN AMPLITUDE
AMPLITUDE 1	0.658	0
AMPLITUDE 2	0.658	0
AMPLITUDE 3	0.1417	0
AMPLITUDE 4	0.1474	0
AMPLITUDE 5	0.1471	0

The above figure shows all the modes in all 3 directions.

CONCLUSION :

From the above simulation we got the following critical frequencies for different modes.

Critical frequency is that frequency at which the natural frequency matches the forcing frequency of the moving body ,thus resulting in vibration at high amplitudes ,causing the body to break or a permanent failure.

So we should design our component in such a manner such that it does not matches its own natural frequency

PLEASE NOTE THAT THE ANIMATED VIDEO OF THE ROTATING SHAFT IS ATTACHED IN THE BELOW LINK

https://drive.google.com/file/d/1HxyaWOHBMEYFaRsPUBJ1DUBj-KZpjJxd/view?usp=drivesdk