REDUCTION OF CABIN NOISE DURING CRUISE CONDITIONS BY STRINGER AND FRAME DAMPING

Control of low-frequency cabin noise is a difficult problem in all commercial aircraft. The subject is analyzed in terms of the response of a pressurized fuselage structure subjected to broadband random pressure fluctuations. It is shown that in the so called “stiffness controlled” region, the structural response and noise transmission may be governed by the resonances of the stiffeners, with the skin acting like an attached mass. As a result, cabin noise at low frequencies may be reduced by application of constrained viscoelastic damping treatments on the stringers and frames of the fuselage. © 1979 American Institute of Aeronautics and Astronautics, Inc., All rights reserved.