This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
Characterization of the Bulk Elastic Properties of Expanding Foams from Impedance Tube Absorption Tests
Technical Paper
2007-01-2191
ISSN: 0148-7191, e-ISSN: 2688-3627
Annotation ability available
Sector:
Language:
English
Abstract
A method is presented to determine the bulk elastic properties of isotropic elastic closed-cell foams from impedance tube sound absorption tests. For such foams, resonant sound absorption is generally observed, where acoustic energy is transformed into mechanical vibration, which in turn is dissipated into heat due to structural damping. This paper shows how the bulk Young's modulus and damping loss factor can be deduced from the resonant absorption. Also, an optimal damping loss factor yielding 100% of absorption at the first resonance is defined from the developed theory. It is shown how this optimal factor can be used to properly design efficient sound absorbing treatments. The method is experimentally tested on one expanding closed-cell foam to find its elastic properties. Using the found properties, sound absorption predictions using an equivalent solid model with and without surface absorption are compared to measurements. Excellent correlations are obtained when considering surface absorption.
Recommended Content
Technical Paper | The Role of a Fiber Decoupler on the Acoustical Performance of Automotive Floor Systems |
Technical Paper | Closed Cell Foam: A Sound Barrier and More |
Technical Paper | Application of Micro-Perforated Panels to Attenuate Noise in a Duct |
Authors
Citation
Chevillotte, F., Panneton, R., Wojtowicki, J., and Chaut, C., "Characterization of the Bulk Elastic Properties of Expanding Foams from Impedance Tube Absorption Tests," SAE Technical Paper 2007-01-2191, 2007, https://doi.org/10.4271/2007-01-2191.Also In
References
- Biot, M. 1956 “The theory of propagation waves in a fluid-saturated porous solid. I. Low frequency range. II. Higher frequency range,” J. Acoust. Soc. Am. 28 168 191
- Allard, J.F. 1993 Propagation of sound in porous media. Modeling sound absorbing materials (Elsevier applied science)
- Ingard, U. 1994 Notes on sound absorption technologies Noise Control Fundation NY
- Wojtowicki, J.-L Panneton, R 2005 “Improving the efficiency of sealing parts for hollow body network,” SAE Tech. Paper, Doc# 2005-01-2279
- Blevins, R.D. 1979 Formulas for natural frequency and mode shape Krieger Publishing co. 2001
- Gibson, L.J. Ashby, M.F. 1999 Cellular solids: structure and properties Cambridge, NY
- Langlois, C. Panneton, R. Atalla, N. 2001 “Polynomial relations for quasi-static mechanical characterization of poroelastic materials,” J. Acoust. Soc. Am. 110 6 3032 3040
- Wojtowicki, J.-L Jaouen, L. Panneton, R. 2004 “New approach for the measurement of damping properties of materials using the Oberst beam,” Rev. Sci. Inst. 75 8 2569 2574