Article
Investigating Nonlinear Models for Health Monitoring in Vibrating Structures
Proceedings of the ASME 2009 International Mechanical Engineering Congress & Exposition IM
(2009)
Abstract
This paper investigates a method of nondestructive health monitoring based on mapping variations in a system’s estimated nonlinear parametric model. The studied system is a slender cantilever beam harmonically excited around its second natural frequency. Known significant nonlinear parameters for this system including quadratic damping and terms due to bending and inertia are considered. This study uses the Continuous Time based nonlinear system identification technique. The method used here has advantages over mappings of the system’s linear parameters, such as natural frequency whose apparent value is shown to change as the amplitude of excitation is increased for physical systems behaving nonlinearly. Crack initiation and growth was effectively identified, but the effectiveness of the method was shown to be a function of the number and nature of the terms included in the model, and the number of records used in the identification process. The use of a simple nonlinear stiffness term and frequency records near resonance produced the best results. This method is shown to identify changes in the system’s behavior well before the failure of the system being studied, suggesting the method may lead users to avoid catastrophic failure in practice.
Keywords
- Inertia (Mechanics),
- Resonance,
- Cantilever beams,
- Fracture (Materials),
- Damping,
- Nonlinear systems,
- Failure,
- Stiffness
Disciplines
Publication Date
November, 2009
DOI
10.1115/IMECE2009-13304
Citation Information
Matthew Leineweber and Timonthy A Doughty. "Investigating Nonlinear Models for Health Monitoring in Vibrating Structures" Proceedings of the ASME 2009 International Mechanical Engineering Congress & Exposition IM Vol. 9 (2009) p. 57 - 62 Available at: http://works.bepress.com/matthew-leineweber/22/