Dynamics of vacuum-sealed, double-leaf partitions

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dc.contributor Mahmoodi, S. Nima
dc.contributor Hubner, James Paul
dc.contributor.advisor Shepard, W. Steve
dc.contributor.author Kavanaugh, Joshua Stephen
dc.date.accessioned 2017-03-01T17:38:46Z
dc.date.available 2017-03-01T17:38:46Z
dc.date.issued 2015
dc.identifier.other u0015_0000001_0002173
dc.identifier.other Kavanaugh_alatus_0004M_12513
dc.identifier.uri https://ir.ua.edu/handle/123456789/2542
dc.description Electronic Thesis or Dissertation
dc.description.abstract The goal of this research is to investigate the feasibility and potential effectiveness of using vacuum-sealed, double-leaf partitions for applications in noise control. Substantial work has been done previously on double-leaf partitions where the acoustics of the inner chamber and mechanical vibrations of structural supports are passively and actively controlled. The work presented here is unique in that the proposed system aims to eliminate the need for active acoustic control of transmitted acoustic energy by removing all the air between the two panels of the double partition. Therefore, the only remaining energy paths would be along the boundary and at the points where there are intermediate structural supports connecting the two panels. The eventual goal of the research is to develop a high-loss double-leaf partition that simplifies active control by removing the need for control of the air cavity and channeling all the energy into discrete structural paths. The work presented here is a first step towards the goal of designing a high-loss, actively-controlled double-leaf partition with an air-evacuated inner chamber. One experiment is conducted to investigate the effects of various levels of vacuum on the response of a double-leaf partition whose panels are mechanically coupled only at the boundary. Another experiment is conducted which investigates the effect of changing the stiffness of an intermediate support coupling the two panels of a double-leaf partition in which a vacuum has been applied to the inner cavity. The available equipment was able to maintain a 99% vacuum between the panels. Both experiments are accompanied by analytical models used to investigate the importance of various dynamic parameters. Results show that the vacuum-sealed system shows some potential for increased transmission loss, primarily by the changing the natural frequencies of the double-leaf partition.
dc.format.extent 121 p.
dc.format.medium electronic
dc.format.mimetype application/pdf
dc.language English
dc.language.iso en_US
dc.publisher University of Alabama Libraries
dc.relation.ispartof The University of Alabama Electronic Theses and Dissertations
dc.relation.ispartof The University of Alabama Libraries Digital Collections
dc.relation.hasversion born digital
dc.rights All rights reserved by the author unless otherwise indicated.
dc.subject.other Mechanical engineering
dc.subject.other Acoustics
dc.subject.other Virology
dc.title Dynamics of vacuum-sealed, double-leaf partitions
dc.type thesis
dc.type text
etdms.degree.department University of Alabama. Dept. of Mechanical Engineering
etdms.degree.discipline Mechanical Engineering
etdms.degree.grantor The University of Alabama
etdms.degree.level master's
etdms.degree.name M.S.


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