Sound Transmission Characteristic through Mechanically Connected Laminated Composite Double Wall Panel
Invited paper
Jadavpur University
Tuesday 2 june, 2015, 11:40 - 12:00
0.1 London (90)
Abstract:
Double wall structural panels are being extensively used in automobiles,
aircraft, ships as well as building partition walls. Double wall panels have
shown marked improvement in terms of transmission loss over traditional
single wall partition except at certain critical frequencies. One of the
earliest works on double wall partition can be attributed to London [1]
which led to the famous London-Beranek model. Since then, several
researchers have contributed significantly in the understanding of the
behavior of sound transmission through double wall panel. Most of the
reported studies are for infinite panels and in the mid to high frequency
region. Bao and his co-workers [2, 3] have carried out some studies on sound
transmission behavior through finite dimensional double wall panels.
However, as reported in the literatures, the effect of curvature and
mechanical links connecting the panels are not systematically investigated.
In the present work, it is therefore attempted to understand the sound
transmission mechanism through mechanically connected double wall panels.
Furthermore, the effect of lightweight laminated composite panels in the
coupled transmission behavior has also been investigated. The effect of the
panel curvature, as is seen in automobiles and aircraft panels, is also
taken into consideration. A free vibration analysis of the structural panels
in-vacuo and the air gap with rigid wall condition is first carried out and
thereafter a coupled relationship using Green’s Theorem is developed to
understand the sound transmission behavior.
1.Transmission of Reverberant Sound through Double Walls, A. London, JASA,
22(2), 1950
2.Active control of sound transmission through a double panel partition, P.
Sas, C. Bao, F. Augusztinovicz and W. Desmet, JSV, 180(4), 1995
3.Analytical study of different approaches for active control of sound
transmission through double walls, J. Pan and C. Bao, JASA, 103(4), 1998