Autor: |
David J. Bamford, James G. McDaniel, Elizabeth A. Magliula, Mark J. Cops, Jay Bliefnick |
Rok vydání: |
2019 |
Předmět: |
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Zdroj: |
The Journal of the Acoustical Society of America. 146:2786-2786 |
ISSN: |
0001-4966 |
DOI: |
10.1121/1.5136653 |
Popis: |
A composite foam consisting of polyurethane foam embedded in metallic foam is fabricated and evaluated for sound absorbing properties. The normal incidence sound absorption coefficient is measured in an impedance tube for three different types of foams including the composite foam, a rigid framed metallic foam, and an elastic framed polyurethane foam. A lumped element model is used to predict the energy dissipation mechanisms, which include viscous and thermal losses, structural losses, and coupling losses at the metal and polyurethane interface. The best performing composite foam increased sound absorption by a factor of 6 (from 0.1 to 0.6) in the low frequency test range (around 600 Hz) and by a factor of 2 (from 0.2 to 0.4) over the entire test frequency range (250–4500 Hz). The composite foam maintains the high static stiffness of the metal foam and exhibits acoustic compliance characteristic of the polyurethane foam. Composites such as those presented in this work are advantageous for engineering applications where combined high stiffness and energy absorption are required. |
Databáze: |
OpenAIRE |
Externí odkaz: |
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