dc.contributor.author	Krauss, Ryan	en
dc.contributor.committeechair	Nayfeh, Ali H.	en
dc.contributor.committeemember	Hendricks, Scott L.	en
dc.contributor.committeemember	Mook, Dean T.	en
dc.contributor.department	Engineering Science and Mechanics	en
dc.date.accessioned	2014-03-14T20:52:11Z	en
dc.date.adate	1998-08-18	en
dc.date.available	2014-03-14T20:52:11Z	en
dc.date.issued	1998-08-04	en
dc.date.rdate	1998-08-18	en
dc.date.sdate	1998-08-04	en
dc.description.abstract	A procedure is presented for using a primary resonance excitation in experimentally identifying the nonlinear parameters of a model approximating the response of a cantilevered beam by a single mode. The model accounts for cubic inertia and stiffness nonlinearities and quadratic damping. The method of multiple scales is used to determine the frequency-response function for the system. Experimental frequency- and amplitude-sweep data are compared with the prediction of the frequency-response function in a least-squares curve-fitting algorithm. The algorithm is improved by making use of experimentally known information about the location of the bifurcation points. The method is validated by using the parameters extracted to predict the force-response curves at other nearby frequencies. We then compare this technique with two other techniques that have been presented in the literature. In addition to the amplitude- and frequency-sweep technique presented, we apply a second frequency-domain technique and a time-domain technique to the second mode of a cantilevered beam. We apply the restoring-force surface method assuming no a priori knowledge of the system and use the shape of the surface to guide us in assuming a form for the equation of motion. This equation is used in applying the frequency-domain techniques: a backbone curve-fitting technique based on the describing-function method and the amplitude- and frequency-sweep technique based on the method of multiple scales. We derive the equation of motion from a Lagrangian and discover that the form assumed based on the restoring-force surface is incorrect. All of the methods are reapplied with the new form for the equation of motion. Differences in the parameter estimates are discussed. We conclude by discussing the limitations encountered for each technique. These include the inability to separate the nonlinear curvature and inertia effects and problems in estimating the coefficients of small terms with the time-domain technique.	en
dc.description.degree	Master of Science	en
dc.identifier.other	etd-71898-14457	en
dc.identifier.sourceurl	http://scholar.lib.vt.edu/theses/available/etd-71898-14457/	en
dc.identifier.uri	http://hdl.handle.net/10919/36912	en
dc.publisher	Virginia Tech	en
dc.relation.haspart	cover.pdf	en
dc.relation.haspart	chapter1.pdf	en
dc.relation.haspart	chapter2.pdf	en
dc.relation.haspart	chapter3.pdf	en
dc.relation.haspart	chapter4.pdf	en
dc.relation.haspart	vita.pdf	en
dc.relation.haspart	bibliography.pdf	en
dc.rights	In Copyright	en
dc.rights.uri	http://rightsstatements.org/vocab/InC/1.0/	en
dc.subject	experimental identification	en
dc.subject	nonlinear beam	en
dc.subject	perturbation methods	en
dc.subject	time-domain techniques	en
dc.subject	frequency-domain techniques	en
dc.title	Experimental Identification of Nonlinear Systems	en
dc.type	Thesis	en
thesis.degree.discipline	Engineering Science and Mechanics	en
thesis.degree.grantor	Virginia Polytechnic Institute and State University	en
thesis.degree.level	masters	en
thesis.degree.name	Master of Science	en

Experimental Identification of Nonlinear Systems

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