Abstract: In order to improve the sound absorption and noise reduction performance of nomex honeycomb sandwich structure, the effects of honeycomb height, the filling content of porous fibers and the opening of microporous skin on the sound absorption coefficient (SAC) and sound transmission loss (STL) of honeycomb sandwich structures are explored. The experiment results indicate that SAC of sandwich structure can be effectively changed by filling sound absorption cotton and skin opening in 0.8 kHz~2.5 kHz. SAC can be improved by the increase of the fiber content. When the filling content of fiber material is 300 g/m², the peak of SAC is 0.84, which increases by 0.16. But the influence of fiber material on STL is weak. Microporous skin is beneficial to play the role of sound absorption of microperforated board and porous fiber, and SAC is greatly improved.

Key words: porous fiber, nomex honeycomb sandwich structure, sound absorption coefficient, sound transmission loss