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A membrane-type acoustic metamaterial with adjustable acoustic properties
Publikationstyp
Journal Article
Date Issued
2016-07-07
Sprache
English
Institut
TORE-URI
Journal
Volume
373
Start Page
1
End Page
18
Citation
Journal of Sound and Vibration (373): 1-18 (2016-07-07)
Publisher DOI
Scopus ID
The proposed design distinguishes itself from other realizations by a stacked arrangement of two MAMs which is inflated using pressurized air. The static pressurization leads to large nonlinear deformations and, consequently, geometrical stiffening of the MAMs which is exploited to adjust the eigenmodes and sound transmission loss of the structure. A theoretical analysis of the proposed inflatable MAM design using numerical and analytical models is performed in order to identify two important mechanisms, namely the shifting of the eigenfrequencies and modal residuals due to the pressurization, responsible for the transmission loss adjustment. Analytical formulas are provided for predicting the eigenmode shifting and normal incidence sound transmission loss of inflated single and double MAMs using the concept of effective mass. The investigations are concluded with results from a test sample measurement inside an impedance tube, which confirm the theoretical predictions.
Subjects
Active
Membrane
Metamaterial
Non-linear
Transmission loss