Sound Transmission through Laminated Composite Cylindrical Shells, Considering Transverse Shear Deformation

Laminated composite shells are increasingly being used in various engineering applications, including aerospace, mechanical, marine, and automotive. In this paper, sound transmission through an infinite laminated composite cylindrical shell is studied in the context of the transmission of airborne sound into aircraft interior. The shell is immersed into an external fluid medium and contains internal fluid, while the airflow in external fluid medium is moving with a constant velocity. Modal impedance method, along with the first-order shear deformation theory (FSDT), is used to calculate the transmission loss (TL), considering three directions of the shell. The TL obtained in this study is compared with that of thin laminated composite obtained by others. The effects of structural properties and flight conditions on TL are studied for a range of values, especially, Mach number, aircraft flight altitude, shell thickness, and warp angle. Comparisons of the transmission loss are made among classical shell theory (CST) and FSDT for laminated composite and isotropic shells, which show close agreements.