Frequency Analysis of a rotating shaft
Frequency analysis of a rotating shaft
The objective of this study is to analyze the various natural frequencies of a rotating disc mounted on a shaft using the frequency analysis module of solidworks simulation.
Natural frequency:
Natural frequency, also known as eigenfrequency, is the frequency at which a system tends to oscillate in the absence of any driving or damping force.
Resonant frequency:
If the oscillating system is driven by an external force at the frequency at which the amplitude of its motion is greatest (close to a natural frequency of the system), this frequency is called resonant frequency.
Importance of this study:
The main purpose of this study is to find the natural frequency of the vibrating system and prevent its operation anywhere those frequencies. In this way, the resonant frequency of the system is not triggered and so the chances of failure of the system is minimized.
Design and initial setup:
1. The shaft and the disc are designed separately and are assembled. The shaft which is 25 mm in diameter is supported by bearings on either side. The shaft diameter on these two ends are 18 mm, which is the bore of the bearings. The disc is of 100 mm in diameter and has a thickness of 10 mm.
2. The frequency analysis is chosen under solidworks simulation. The number of modes is set as 5 in the frequency setup dialog box. An iterative solver (FFE plus) solver is chosen.
3. Then a bearing support is provided on both the ends of the shaft. The mesh is then created with a medium element size. The model is now ready to be solved.
Results:
Once the model is soved, 5 different modes of the frequencies are provided.
Mode shape 1:
Mode shape 2:
Mode shape 3:
Mode shape 4:
Mode shape 5:
Conclusion:
Thus, a list of resonant frequencies were computed for the rotating shaft using frequency analysis system of solidworks simulation.
For safe operation, it should be ensured that the rotating shaft is not operated anywhere near these resonant frequencies.