Laminated Composite Double Walled Cylindrical Shells

An analytical study is conducted in this paper to determine the characteristics of sound transmission through laminated composite double-walled thin cylindrical shells with infinite length. It is assumed that the external and internal fluid media surrounded the shells, and there is fluid existence in the annular space between them. A uniform flow exists with a constant velocity in the external medium. An exact solution is obtained by solving the classical shell equations and acoustic wave equations simultaneously. Transmission losses obtained from the numerical solution in this paper are compared with the results of other investigators for composite single-walled cylindrical shell. Comparison revealed good agreement. Finally, the effects of different source conditions, structural, fluid and gap properties as well as flight conditions on TL have been studied for a range of values, specifically; incident angle of the plane wave, Mach number and flight altitude of aircraft, thickness and curvature of shells lay-up stacking sequence and damping.