On Sound Transmission into a Stiffened Cylindrical Shell with Rings and Stringers Treated as Discrete Elements
In the context of the transmission of airborne noise into an aircaft fuselage, a mathematical model is presented for the transmission of an oblique plane sound wave into a finite cylindrical shell stiffened by stringers and ring frames. The rings and stringers are modeled as discrete structural elements. The numerical case studies was typical of a narrow-bodied jet transport fuselage. The numerical results show that the ring-frequency dip in the transmission loss curve that is present for a monocoque shell is still present in the case of a stiffened shell. The ring frequency effect is a result of the cylindrical geometry of the shell. Below the ring frequency, stiffening does not appear to have any significant effect on transmission loss, but above the ring frequency, stiffeners can enhance the transmission loss of a cylindrical shell.
L. R. Koval, "On Sound Transmission into a Stiffened Cylindrical Shell with Rings and Stringers Treated as Discrete Elements," Journal of Sound and Vibration, Elsevier, Jan 1980.
The definitive version is available at http://dx.doi.org/10.1016/0022-460X(80)90723-3
Mechanical and Aerospace Engineering
Article - Journal
© 1980 Elsevier, All rights reserved.