Laboratory for Dynamics of Machines and Structures 
Structural-acoustic model of a rectangular plate-cavity system with an attached distributed mass and internal sound source: theory and experiment
 M.Pirnat, G.Čepon and M.Boltežar
Journal of Sound and Vibration, Volume 333, Issue 7, 31 March 2014, Pages 2003-2018

download pdf   http://dx.doi.org/10.1016/j.jsv.2013.11.044
Abstract
In this paper three approaches are combined to develop a structural-acoustic model of a rectangular plate-cavity system with an attached distributed mass and internal sound source. The First approach results from a recently presented analysis based on the Raylegih-Ritz method and is used to circumvent the difficulties in obtaining the natural frequencies and mode shapes of a plate with an attached, distributed mass. Furthermore, di erent plate boundary conditions can be accommodated. The resulting mode shapes are de ned as continuous functions; this is advantageous as they can be directly used in the second approach, i.e., the classic modal-interaction approach in order to obtain the coupled equations of the system. Finally, in the third approach a group of point sources emitting a pressure pulse in the time domain is used to model an internal sound source. For the validation of the developed model an experiment was conducted in two con gurations using a simply supported aluminium plate and a clamped plate coupled with a plexiglas box containing a loudspeaker. Good agreement was found between the analytical and experimental data.
Authors

R&D

Miha Pirnat, PhD

  Kolektor Etra d.o.o.
  miha.pirnat@kolektor.com
  
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Professor

Gregor Čepon, PhD

  Ladisk, Faculty of Mechanical Engineering, University of Ljubljana
  gregor.cepon@fs.uni-lj.si
  +386 1 4771 229
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Professor

Miha Boltežar, PhD

  Ladisk, Faculty of Mechanical Engineering, University of Ljubljana
  miha.boltezar@fs.uni-lj.si
  +386 1 4771 608
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