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Some Remarks on the Zero Frequency Modes

Published online by Cambridge University Press:  04 July 2016

B. Tabarrok*
Affiliation:
Assistant Professor in the Mechanical Engineering Department, University of Toronto

Extract

In the theory of small vibrations the motion of a system can be characterised in terms of either geometrically compatible displacements or dynamically admis-sable impulses (1,2,3). However, the number of generalised displacements required to describe the motion of a system need not be the same as the number of generalised impulses required for the same purpose. The reason for this difference is that in either or both formulations certain zero frequency modes may be present. If the co-ordinates which describe such modes are eliminated then the number of displacement and impulse co-ordinates required to describe the oscillatory modes will be equal and one can then transform one formulation to the other by means of Legendre's transformation(4).

Type
Research Article
Copyright
Copyright © Royal Aeronautical Society 1968 

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References

1. Toupin, R. A. A Variational Principle for the Mesh-Type Analysis of a Mechanical System. Trans ASME 74, J Appl Mech, pp 151152, 1952.Google Scholar
2. Crandall, S. H. Complementary Extremum Principles for Dynamics. Proceedings of 9th International Congress of Applied Mechanics, Vol 5, Brussels, 1957.Google Scholar
3. Karnopp, B. H. and Tabarrok, B. On the Application of the Complementary Energy Method to the Analysis of Dynamic System (submitted for publication). Google Scholar
4. Karnopp, B. H. On Complementary Variational Principles in Linear Vibrations. Journal of the Franklin Institute, July 1967.Google Scholar
5. Frazer, R. A., Duncan, W. J. and Collar, A. R. Elementary Matrices. CUP, 1938.Google Scholar
6. White, D. C. and Woodson, H. H. Electromechanical Energy Conversion. John Wiley, New York, 1953.Google Scholar
7. Williams, D. Theory of Aircraft Structures. Edward Arnold, London, 1960.Google Scholar