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Near-periodicity in acoustically excited stiffened plates and its influence on vibration, radiation and sound insulation

Brunskog, Jonas LU (2004) In Acta Acustica united with Acustica 90(2). p.301-312
Abstract
Due to variabilities in the material, the geometrical configuration, or the manufacturing properties, a structure that is designed to be spatially periodic cannot be exactly periodic. The presence of small irregularities in a nearly periodic structure may influence the propagation of the vibration field, the field being localised. A number of papers have addressed such localisation phenomena. This paper will instead focus on the mean vibration field and its influence on sound radiation and sound insulation in a plate stiffened by supports or beams. The approach is to seek a formal solution with the aid of spatial transform technique (similar to the perfect periodic case) and then apply the expected value operator to the solution. Two... (More)
Due to variabilities in the material, the geometrical configuration, or the manufacturing properties, a structure that is designed to be spatially periodic cannot be exactly periodic. The presence of small irregularities in a nearly periodic structure may influence the propagation of the vibration field, the field being localised. A number of papers have addressed such localisation phenomena. This paper will instead focus on the mean vibration field and its influence on sound radiation and sound insulation in a plate stiffened by supports or beams. The approach is to seek a formal solution with the aid of spatial transform technique (similar to the perfect periodic case) and then apply the expected value operator to the solution. Two assumptions must then be introduced: 1) The reaction forces are statistically independent of a phase-term that is due to the irregularity, and 11) the mean field is periodic. The approach is presented in general terms, the specific configuration (a stiffened plate) being presented as an example. Numerical results are presented and discussed, and it can be seen that the small irregularities cause an increase in stiffness and damping (when material damping is present). (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Acta Acustica united with Acustica
volume
90
issue
2
pages
301 - 312
publisher
Hirzel Verlag
external identifiers
  • wos:000221044100011
  • scopus:1942487222
ISSN
1436-7947
language
English
LU publication?
yes
id
827b47ec-89f7-4679-95d4-68839cd734fd (old id 280558)
alternative location
http://www.ingentaconnect.com/content/dav/aaua/2004/00000090/00000002/art00011
date added to LUP
2007-10-17 13:23:40
date last changed
2017-01-01 07:21:40
@article{827b47ec-89f7-4679-95d4-68839cd734fd,
  abstract     = {Due to variabilities in the material, the geometrical configuration, or the manufacturing properties, a structure that is designed to be spatially periodic cannot be exactly periodic. The presence of small irregularities in a nearly periodic structure may influence the propagation of the vibration field, the field being localised. A number of papers have addressed such localisation phenomena. This paper will instead focus on the mean vibration field and its influence on sound radiation and sound insulation in a plate stiffened by supports or beams. The approach is to seek a formal solution with the aid of spatial transform technique (similar to the perfect periodic case) and then apply the expected value operator to the solution. Two assumptions must then be introduced: 1) The reaction forces are statistically independent of a phase-term that is due to the irregularity, and 11) the mean field is periodic. The approach is presented in general terms, the specific configuration (a stiffened plate) being presented as an example. Numerical results are presented and discussed, and it can be seen that the small irregularities cause an increase in stiffness and damping (when material damping is present).},
  author       = {Brunskog, Jonas},
  issn         = {1436-7947},
  language     = {eng},
  number       = {2},
  pages        = {301--312},
  publisher    = {Hirzel Verlag},
  series       = {Acta Acustica united with Acustica},
  title        = {Near-periodicity in acoustically excited stiffened plates and its influence on vibration, radiation and sound insulation},
  volume       = {90},
  year         = {2004},
}