5.10  Discussions

Good agreement between the theoretically calculated natural frequency and the experimental one is found. The correction for the mass of the sensor will improve the correlation better. The present theoretical calculation is based on the assumption that one end of the cantilever beam is properly fixed. However, in actual practice it may not be always the case because of flexibility in support. By considering all the precautions and by using the procedure step by step with proper coordination with the subsystem, measuring instruments, data acquisition system and vibration measuring software, the result can be improved.To minimize error in the result, user is suggested to use sensors and other measuring instruments with high sensitivity and minimize the noise in measuring data. User is also suggested to repeat the experiment with patience. 

 5.11  Precautions during Experimentations and Analyses

 1.      Fixed end condition of the cantilever beam could be ensured by properly gripping one end of the beam.

2.      Care should be taken that the cables of accelerometer should not affect the beam motion.

3.      The mass of the accelerometer should be small as compared to beam mass.

4.      The power of excitation should be proper, too less power may cause of insufficient vibration and too high power may cause of damage of the system.

5.      Select the sweep rate which should not either very less or very high. Usually sweep rate 2 or 3 Hz/sec is suggested.

6.      Placement of sensors and exciter stinger, should not be at node.

5.12  References

1.      Meirovitch, L., 1967, Analytical methods in vibration, Ccollier-MacMillan Ltd., London.

2.      Thomson, W.T., 2007, Theory of vibration with application, Kindersley Publishing, Inc., London.

3.      Rao, J. S, and Gupta, K., Introductory Course on Theory and Practice of Mechanical Vibrations, New Age International, New Delhi.