Daneshjou - Assistante professor Department of Mechanical Engineering Iran University of Science and Technology
Ali Nouri - phD student - Faculty of Sattary Air University
Rohollah Telebitooti - phD student Department of Mechanical Engineering Iran University of Science and Technology

Composite structures are often used in aircraft because of advantages offered by a high strength to weight ratio. 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 in external fluid medium and contains internal fluid, and airflow in external fluid medium is moving with a constant velocity. An exact solution is obtained by solving the classical laminated composite shell vibration equations and acoustic wave equations simultaneously. Transmission losses obtained from numerical solutions are compared with that of “Koval”. The effects of different source condition, structural properties and flight conditions on TL are studied for a range of values, especially, incident angle of the plane wave, Mach number, flight altitude of aircraft, angle of warp and structural damping.

Wave, Transmission loss, Laminated composite shell, Frequency