Civil Engineering Reference
In-Depth Information
If K and F n are rewritten in terms of u and u
exp j k 0 L x
2
r 2 1 / 2
u 2
u 2
= exp
u cos ϕ
r sin ϕ
+
u
j k t L x
2
K (u,u )
F n (u,u )
=
;
+
u 2
r 2 1 / 2
u 2
+
(12.A.8)
Equation (12.A.6) leads to
d v K (u,u ) d u
d v K (u,u ) d u
= 2
2
2
u
0
2
2
u) K (u,u ) d u
+
( 2
0
0
2
u
0
(12.A.9)
Using these transformations the radiation impedance becomes:
2
2
0 ω L y
4 π
u ) K (u,u )F n (u,u ) d u d u
Z
=
( 2
u)( 2
(12.A.10)
0
0
1and u
u +
Finally, the change of variables u
u
+
1isusedtotransformthe
integration domain into [ - 1,1] :
1
1
0 ω L y
4 π
u ) K (u
+ 1 ,u
+ 1 ,u
+ 1 ) d u d u
Z
=
( 1
u)( 1
+ 1 )F n (u
1
1
(12.A.11)
This last integral can be evaluated numerically.
References
Atalla, N., Ghinet, S. and Haisam, O. (2004) Transmission loss of curved sandwich composite
panels. 18th ICA , Kyoto.
Duval, A., Dejaeger, L., Baratier, J. and Rondeau, J-F (2008) Structureborne and airborne Insertion
Loss simulation of trimmed curved and flat panels using Rayon-VTM-TL: implications for
the 3D design of insulators. Automobile and Railroad Comfort - November 19 - 20, Le Mans,
France.
Ghinet, S. and Atalla, N. (2002) Vibro-acoustic behaviour of multi-layer orthotropic panels. Cana-
dian Acoustics 30 (3) 72 - 73.
Ghinet, S. and Atalla, N. (2006) Vibro-acoustic behaviours of flat sandwich composite panels.
Transactions of Canadian Soc. Mech. Eng J . 30 (4).
Leppington, F.G., Broadbent, E.G., & Heron, K.H. (1982) The acoustic radiation efficiency from
rectangular panels. Proc. R. Soc. London. 382 , 245.
Leppington, F. G, Heron, K. H. & Broadbent, E. G. (2002) Resonant and non-resonant noise
through complex plates. Proc. R. Soc. Lond . 458 , 683 - 704.
Nelisse, H., Onsay, T. and Atalla, N. (2003) Structure borne insertion loss of sound package com-
ponents. Society of Automotive Engineers , SAE paper 03NVC-185, Traverse City, Michigan.
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