Frequency Analysis of a rotating shaft

Aim: To perform the frequency analysis of rotating shaft and find out the critical frequencies of a rotating shaft in Solidworks.

Objective:

• Design the rotating shaft using solidworks based on any desired dimensions.
• List the resonant frequencies

Theory:

Resonant frequency is the oscillation of a system at its natural or unforced resonance. Resonance occurs when a system is able to store and easily transfer energy between different storage modes, such as kinetic energy or potential energy as you would find with a simple pendulum.

Resonance: The increase in amplitude of oscillation of an electric or mechanical system exposed to a periodic force whose frequency is equal or close to the natural undamped frequency of the system.

Mode: The mode is a statical term that refers to the most frequency occurring number found in a set of numbers.

Mode shape: The deformed shape of the structure at a specific natural frequency of vibration is termed its normal mode of vibration.

Modelling of rotating shaft

Draw using solidworks

Assembly of rotating shaft

• Result

The result we get would be 5 different modes each measured using different amplitude or natural frequencies.

• Mode 1

• animation for frequency analysis of rotating shaft

• Mode 2

• animation for frequency analysis of rotating shaft

• Mode 3

• Animation for frequency analysis of rotating shaft

• Mode 4

• Animation for frequency analysis of rotating shaft

• Mode 5

• Animation for frequency analysis of rotating shaft

• The different resonant or critical frequencies obtained are as follows:

• Plot for Frequency vs. Mode No.

Conclusion

From this analysis it is clear that the frequency varies to different mode shapes and its amplitude is directly proportional to the frequency inducing the resonance.