A Modified Honeycomb Panel to Improve Sound Transmission Loss

Abstract

Honeycomb panels are widely used in aviation and aerospace industry as well as in buildingindustry because of the properties of lightweight and high bending stiffness. However, the soundtransmission loss of the panel is often low since the coincident frequency of the panel usually lies belowkHz. Previous results show that a single-faced honeycomb panel may acoustically perform much better,especially when it is combined with absorptive materials. This idea is further developed to overcomedrawbacks. An improved concepts of honeycomb panel is presented, which keeps the basic propertiesof a honeycomb panel, while the coincident phenomenon in audible frequency is avoided. Thetheoretical consideration behind this design is discussed. The idea is then tested experimentally. Theweighted apparent sound reduction index of the modified honeycomb panel is 4 dB higher than anordinary honeycomb panel with similar thickness and similar surface density.