Date of Award
Spring 2018
Document Type
Thesis
Degree Name
Master of Science (MS)
Department
Mechanical & Aerospace Engineering
Committee Director
Sebastian Bawab
Committee Member
Onur Bilgen
Committee Member
Thomas Alberts
Abstract
While the mathematical foundation for modal analysis of continuous systems has long been established, flexible structures have become increasingly widespread and developing tools for understanding their mechanics has become increasingly important. Cantilever beams and plates, in particular, have been extensively studied due to their practical importance as approximations of more complex structures. The focus of this thesis is on understanding the dynamics of vibrating cantilever beams and plates through analytical and experimental investigation. Various models for the mechanics of these structures, of varying physical fidelity, are described and compared. A fiber optic sensing system is utilized to experimentally acquire distributed strain measurements, which are used to estimate the mode shapes and natural frequencies for the cantilever structures. These experimental estimates are compared with analytical and numerical solutions corresponding to the models previously introduced. Next, a detailed case study is described which demonstrates the nonlinear response in a cantilever beam's first mode and implements an empirical procedure for estimating a variable parameter model which accounts for its varying system parameters. By implementing the described identification methods, parameter variations due to a system's nonlinear response are included in a modified linear model and significantly reduce the errors in predicted response. Based on this research, methods to experimentally estimate and validate the mode shapes and system parameters can be implemented for other beam- and plate-like structures.
Rights
In Copyright. URI: http://rightsstatements.org/vocab/InC/1.0/ This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s).
DOI
10.25777/qeej-ec33
ISBN
9780438022010
Recommended Citation
Heaney, Patrick S..
"Distributed Sensing and System Identification of Cantilever Beams and Plates in the Presence of Weak Nonlinearities"
(2018). Master of Science (MS), Thesis, Mechanical & Aerospace Engineering, Old Dominion University, DOI: 10.25777/qeej-ec33
https://digitalcommons.odu.edu/mae_etds/40