Hostname: page-component-7479d7b7d-8zxtt Total loading time: 0 Render date: 2024-07-11T16:23:26.531Z Has data issue: false hasContentIssue false

Non-linear vibration of rotating cantilever blades treated by the Ritz averaging process

Published online by Cambridge University Press:  04 July 2016

J. S. Rao
Affiliation:
Indian Institute of Technology, Kharagpur
W. Carnegie
Affiliation:
University of Surrey, Guildford

Extract

The prediction of the forced vibration response of rotating cantilever blading is of considerable importance in the design of turbine and compressor blading where the rotational speeds are relatively high. Non-linearities in the blades arise from the effects of Coriolis accelerations due to the rotation of the blades mounted on the periphery of the disc.

Lo and Renbarger derived the differential equations of motion of a cantilever beam mounted on a rotating disc at a given stagger angle and show, for a linear case, that the frequencies of a bar vibrating transversely to a plane inclined at an angle to the plane of rotation can be found by a simple transformation of the frequencies of vibration perpendicular to the plane of rotation. Boyce, Di Prima and Handelman applied the Rayleigh-Ritz and Southwell methods to the case of a turbine blade vibrating perpendicular to the plane of rotation and determined the upper and lower bounds of the natural frequencies.

Type
Technical Notes
Copyright
Copyright © Royal Aeronautical Society 1972 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1. Lo, W. and Renbarger, J. Bending vibrations of a rotating beam. First US National Congress of Applied Mechanics, p. 75, 1952.Google Scholar
2. Boyce, W. E., Di Prima, R. C. and Handelman, G. H. Vibrations of rotating beams of constant section. Second US National Congress of Applied Mechanics, p. 165, 1954.Google Scholar
3. Boyce, W. E. Effect of hub radius on the vibrations of a uniform bar. Journal of Applied Mechanics, p. 287, 1956.Google Scholar
4. Carnegie, W. Vibrations of rotating cantilever blading: theoretical approaches to the frequency problem based on energy methods. Journal of Mechanical Engineering Science, Vol 1, No 3, p. 235, 1959.Google Scholar
5. Schilhansl, M. J. Bending frequency of a rotating cantilever beam. Journal of Applied Mechanics, p. 28, 1958.Google Scholar
6. Carnegie, W., Stirling, C and Fleming, J. Vibration characteristics of turbine blading under rotation. Paper 22, Applied Mechanics Convention, Cambridge, April 1966.Google Scholar
7. Rao, J. S. Flexural vibration of turbine blades. Paper under publication, Archiwum Budowy Maszin.Google Scholar
8. Rao, J. S. Flexural vibration of rotating cantilever beams. Paper under publication, Journal of Aeronautical Society of India. Google Scholar
9. Lo, H. A non-linear problem in the bending vibration of a rotating beam. Journal of Applied Mechanics, p. 461, 1952.Google Scholar
10. Isakson, G. and Eisley, J. G. Natural frequencies in bending of twisted rotating and non-rotating blades. NASA Report: Technical Note D371.Google Scholar
11. Rao, J. S. and Carnegie, W. Non-linear vibrations of rotating cantilever beams. The Aeronautical Journal of the Royal Aeronautical Society, Vol 74, p 161, February 1970.Google Scholar
12. Carnegie, W. The application of variational method to derive the equations of motion of vibrating cantilever blading under rotation. Bulletin of Mechanical Engineering Education, Vol. 6, p 29, 1967.Google Scholar