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Dynamical signatures of gearbox vibrations


Zaremba, Slawomir M. (1998) Dynamical signatures of gearbox vibrations. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/ab9t-b513.


The applicability of a dynamical systems approach to the analysis of gearbox vibration signatures is investigated. The signal acquired from a standard one-step helical gearbox is analyzed and the existence of the low-dimensional nonlinear and chaotic behavior is examined. For this purpose, the criteria of broadband spectrum, sensitivity to initial conditions, positive Lyapunov exponents, and short-term dynamical predictability are applied. The largest Lyapunov exponent is also used to quantify the predictability of the measured time series and a surrogate data test is performed to confirm that the analyzed signal is unlikely to correspond to a linear stochastic time-invariant model. To confirm the applicability of a dynamical systems approach, forecasts of the gearbox time series are produced, using various predictors in the state space. Several methods of dynamical signal separation are also discussed. Finally, a family of statistics is proposed, on the basis of geometric features of the system dynamics in the state space, to serve as dynamical monitoring tools for observing changes in the operating conditions. These are tested using several models of dynamical systems which exhibit behavior similar to that observed in the actual gearbox. The most promising monitoring statistics are recommended for additional studies of gearboxes.

Item Type:Thesis (Dissertation (Ph.D.))
Degree Grantor:California Institute of Technology
Division:Engineering and Applied Science
Major Option:Applied Mechanics
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Caughey, Thomas Kirk (advisor)
  • Beck, James L. (advisor)
Thesis Committee:
  • Unknown, Unknown
Defense Date:10 September 1997
Record Number:CaltechETD:etd-02082008-160817
Persistent URL:
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:561
Deposited By: Imported from ETD-db
Deposited On:11 Mar 2008
Last Modified:16 Apr 2021 22:22

Thesis Files

PDF (Zaremba_sm_1998.pdf) - Final Version
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