Title: Predicting acoustic transmission loss through laminated glass with air and porous layers

Authors: Saurabh Suresh; Teik C. Lim; Jeff Kastner

Addresses: Vibro-Acoustics and Sound Quality Research Laboratory, School of Dynamic Systems, Mechanical Engineering, University of Cincinnati, 598 Rhodes Hall, P.O. Box 210072, Cincinnati, OH 45221-0072, USA. ' Vibro-Acoustics and Sound Quality Research Laboratory, School of Dynamic Systems, Mechanical Engineering, University of Cincinnati, 598 Rhodes Hall, P.O. Box 210072, Cincinnati, OH 45221-0072, USA. ' Gas Dynamics and Propulsion Laboratory, School of Aerospace Systems, University of Cincinnati, 745 Baldwin Hall, P.O. Box 210070, Cincinnati, OH 45221-0072, USA

Abstract: This study analyses the sound transmission characteristic of various laminated glass designs with application to motor vehicles. The porous interlayer in the laminated glass is filled with polyvinyl butyral (PVB) that serves as an acoustic damper. To model the physics behind the sound transmission losses of the fluid, solid and porous layers, acoustic noise transfer matrices are used to relate the dynamic characteristics of two interlayer points in the laminated glass. The porous model includes the effect of the variation in porosity on Poisson's ratio involving the wave number as well as the bulk modulus. Furthermore, an interface matrix is introduced, which defines the dynamic interaction at the interface of every layer. The addition of a fluid layer, like air, yields an interesting phenomenon of two coincidence dips. Finally, a set of parametric studies are performed to observe the transmission loss characteristic due to changes in glass thickness and porous layer.

Keywords: transmission loss; laminated glass; porous layers; transfer matrix; acoustic wave propagation; automotive windshields; vehicle noise; interior noise; vehicle cabins; sound transmission; noise transmission; modelling; polyvinyl butyral; PVB; acoustic dampers; porosity; fluid layer; air layer.

DOI: 10.1504/IJVNV.2012.048168

International Journal of Vehicle Noise and Vibration, 2012 Vol.8 No.3, pp.237 - 260

Available online: 23 Jul 2012 *

Full-text access for editors Access for subscribers Purchase this article Comment on this article