Determination of the Eccentricity of a Rotor by Impulse Excitation Technique of Vibration

Abstract:

The aim of this paper is the development and validation of an impulse excitation technique to determine static imbalance of a rotor. The experimental measurement of the vibroacustic response is carried out by using a condenser microphone. In determining the center of mass three measurements are needed: one in plane flexure, and other out of the plane flexure, to which is added a measurement for a balanced rotor. By the means of Finite Element Method (FEM), the natural frequencies and shape modes of two rotor specimens are determined. The analysis is carried out in balanced condition as well as unbalanced one, after artificially induced imbalance. The vibration responses of the specimens, in free-free conditions, are carried out using algorithms based on Fast Fourier Transform (FFT). To validate the results of the modal parameters estimated using Finite Element Analysis (FEA) these are compared with experimental ones.

• Periodical: Applied Mechanics and Materials (Volume 801)
• Pages: 176-181
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.801.176
• Online since: October 2015
• Authors: Ion Crâştiu, Liviu Bereteu*, Dorin Simoiu
• Keywords: FEM Analysis, FFT Algorithm, Impulse Excitation Method, Rotor, Static Imbalance

References

[1] Y., Chen, On the vibration of beams or rods carrying a concentrated mass. Journal of Applied Mechanics, 30. 2, (1963), 310-311.

DOI: 10.1115/1.3636537

[2] M. A., De Rosa, C., Franciosi, and M. J., Maurizi. On the dynamic behaviour of slender beams with elastic ends carrying a concentrated mass, Computers & structures 58. 6 (1996), 1145-1159.

DOI: 10.1016/0045-7949(95)00199-9

[3] Y., Yesilce ,O., Demirdag, S., Catal, Free vibrations of a multi-span Timoshenko beam carrying multiple spring-mass systems, Sadhana Vol. 33. 4, (2008), 385–401.

DOI: 10.1007/s12046-008-0026-1

[4] N.M., Auciello, Transverse vibration of a linearly tapered cantilever beam with tip mass of rotatory inertia and eccentricity. Journal of Sound Vibration 194 (1), (1996), 25-34.

DOI: 10.1006/jsvi.1996.0341

[5] S. A. M., Lajimi, G. R., Heppler, Free vibration and buckling of cantilever beams under linearly, varying axial load carrying an eccentric end rigid body, Transactions of the Canadian Society for Mechanical Engineering, Vol. 37, No. 1, (2013).

DOI: 10.1139/tcsme-2013-0006

[6] S. A. M., Lajimi, and G. R., Heppler. Eigenvalues of an axially loaded cantilever beam with an eccentric end rigid body., arXiv preprint arXiv: 1401. 3212 (2014).

[7] ASTME-1876-01, Standard Test Method for Dynamic Young's Modulus, Shear Modulus, and Poisson's Ratio by Impulse Excitation Technique of Vibration, (2002).

DOI: 10.1520/e1876-22

[8] L., Bereteu, M., Vodă, D. R., Pascu E., Nyaguly, Influence of some oxide coating layers on the mechanical properties of steel plates, Advanced Materials Research Vol 1111 (2015), 91-96.

DOI: 10.4028/www.scientific.net/amr.1111.91

[9] A., Perescu, L., Bereteu, D., Simoiu, E., Nyaguly, Nondestructive method for the determination of the elastic properties of welded aluminum plates, Advanced Materials Research, vol 1111 (2015), 73-78.

DOI: 10.4028/www.scientific.net/amr.1111.73