Sound absorption performance of a micro perforated sandwich panel with honeycomb-hierarchical pore structure core

A new micro perforated sandwich panel with honeycomb-hierarchical pore structure core is designed and prepared in this study. Carbonized cotton with hierarchical pore structure is combined with a micro perforated honeycomb core sandwich panel, which enhances the sound-absorbing performance of the structure without significantly increasing its weight. The experiment showed that pure carbonized cotton filling can improve the average sound absorption coefficient (at 125, 250, 500, 1000, 2000, and 4000 Hz) of the structure from 0.220 to 0.558, and hierarchical pore structure can further improve the average sound absorption coefficient to 0.626. Meanwhile, appropriate theoretical and finite element models are established, with 16.8 % and 8.6 % error respectively based on the predicted average sound absorption coefficient relative to experimental results.