Recent experiences in phenomenological identification of nonlinear interactions in structures are presented. Free oscillations of quadratically and cubically coupled pairs of oscillators are analytically studied to illustrate nonlinear interactions between structural modes involved in two-to-one and one-to-one frequency relationships. In light of this analytical study, results obtained from application of the Eigensystem Realization Algorithm (ERA) toward identification of a beam-mass structure with a two-to-one frequency relationship and quadratic coupling are presented and discussed. The internal resonance in the structure causes the identified damping coefficients to be oscillatory and to assume negative values. The present effort should be of relevance to the identification of structural systems in which factors, such as symmetry, modal density, frequency relationships, and flexibility contribute to the likelihood that nonlinear interactions may occur.
|Number of pages||6|
|Journal||Journal of Guidance, Control, and Dynamics|
|State||Published - Mar 1994|
Bibliographical noteFunding Information:
The work of the first two authors was supported by the Army Research Office under Grant DAAL03-89-K-0180 and the Office of Naval Research under Contract N00014-90-J-1149. We thank Cheri E. Tanner of NASA Langley Research Center and the reviewers for providing helpful suggestions.
ASJC Scopus subject areas
- Aerospace Engineering
- Applied Mathematics
- Electrical and Electronic Engineering
- Control and Systems Engineering
- Space and Planetary Science