Theoretical and Experimental Identification of Nonlinear Vibrationg Structures for Oil-Film Bearing
| Autor: | Yann-Jy Yang, 楊燕枝 |
|---|---|
| Rok vydání: | 1995 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 83 This thesis is concerned with the oil-film bearing system that is supported by a rigid bearing at one end and a fluid lubricated bearing at the other side where an unloaded symmetric rotor attached nearby. The vibration amplitudes in this system are large enough to perturb the normal operation. Then, to offer a mathematical model for such a nonlinear system such that the vibration phenomena can be controlled and suppressed well is of an important issue. In this thesis, we aim to identify such a nonlinear system experimentally, which has never been carried out before. Due to the fact that, when the system is subjected to a peri- odic external force, the response of the oil-film bearing is periodic, we apply an identification method based on the prin- ciple of harmonic balance to deal with such a highly nonlinear system. We first examine the bifurcation and vibrating phenomena of our oil-film bearing system experimentally. The equations of motion including the nonlinear fluid force terms are adapted and discussed fully. Second, the feasibility of the method based on the principle of harmonic balance and DFT technique in frequency domain is investigated by applying to a single- and multi-degree- of-freedom numerically. At last, we apply this method to our oil-film bearing system experimentally and find that the iden- tified results are well in agreement with our experimental data. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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