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Noise radiation from an open grid bridge

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Date Issued:
1994
Summary:
When a vehicle crosses the grid section of an open grid or bascule bridge, a tonal noise is generated. The tonal character of the noise is a consequence of the periodic excitation of both the tire and the grid, that comes from the interaction between the vehicle tire and the periodic grid members. In this thesis, the parameters that control the level and frequency of the generated noise are investigated, with emphasis on understanding the contribution to the overall noise level from the vibrations of the grid. Field and laboratory measurements have been performed, together with analytical analysis, on sample grid designs. By determining the acoustic radiation efficiency of the grid, the noise contribution from the grid vibrations is estimated by combing the radiation efficiency with the field measured vibration levels. The results of this study show that the contribution from the grid is small compared to that which may be coming from the vibration of the tire. Without first reducing tire noise, structural modifications to the grid in the form of damping or acoustic baffles will not produce any significant noise reduction.
Title: Noise radiation from an open grid bridge.
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Name(s): Tournour, Michel Andre.
Florida Atlantic University, Degree grantor
Cuschieri, Joseph M., Thesis advisor
College of Engineering and Computer Science
Department of Ocean and Mechanical Engineering
Type of Resource: text
Genre: Electronic Thesis Or Dissertation
Issuance: monographic
Date Issued: 1994
Publisher: Florida Atlantic University
Place of Publication: Boca Raton, Fla.
Physical Form: application/pdf
Extent: 104 p.
Language(s): English
Summary: When a vehicle crosses the grid section of an open grid or bascule bridge, a tonal noise is generated. The tonal character of the noise is a consequence of the periodic excitation of both the tire and the grid, that comes from the interaction between the vehicle tire and the periodic grid members. In this thesis, the parameters that control the level and frequency of the generated noise are investigated, with emphasis on understanding the contribution to the overall noise level from the vibrations of the grid. Field and laboratory measurements have been performed, together with analytical analysis, on sample grid designs. By determining the acoustic radiation efficiency of the grid, the noise contribution from the grid vibrations is estimated by combing the radiation efficiency with the field measured vibration levels. The results of this study show that the contribution from the grid is small compared to that which may be coming from the vibration of the tire. Without first reducing tire noise, structural modifications to the grid in the form of damping or acoustic baffles will not produce any significant noise reduction.
Identifier: 15046 (digitool), FADT15046 (IID), fau:11824 (fedora)
Collection: FAU Electronic Theses and Dissertations Collection
Note(s): College of Engineering and Computer Science
Thesis (M.S.E.)--Florida Atlantic University, 1994.
Subject(s): Bridges--Design and construction
Bridges, Steel plate deck
Bridges--Noise
Noise control
Bridges--Vibration
Held by: Florida Atlantic University Libraries
Persistent Link to This Record: http://purl.flvc.org/fcla/dt/15046
Sublocation: Digital Library
Use and Reproduction: Copyright © is held by the author, with permission granted to Florida Atlantic University to digitize, archive and distribute this item for non-profit research and educational purposes. Any reuse of this item in excess of fair use or other copyright exemptions requires permission of the copyright holder.
Use and Reproduction: http://rightsstatements.org/vocab/InC/1.0/
Host Institution: FAU
Is Part of Series: Florida Atlantic University Digital Library Collections.