Heterogeneously perforated honeycomb-corrugation hybrid sandwich panel as sound absorber

Abstract

An ultra-lightweight sandwich panel with perforated honeycomb-corrugation hybrid (PHCH) core is innovated as a novel sound absorber, which demonstrates great sound absorption as well as excellent mechanical performance. Based on the hybrid-cored sandwich panel, small perforations of different diameters distributed heterogeneously on both the top facesheet and the corrugation are introduced to obtain perfect sound absorption at low frequencies with almost no deterioration in mechanical performance. Theoretical models for sound absorption coefficient and bending stiffness are established, then verified by numerical simulations. With specific mass taken into consideration, an integrated index is proposed to further evaluate the acoustic-mechanical property of the hybrid sandwich. It is found that the PHCH with thinner honeycomb always performs better at low frequencies, and the facesheet is more important to the acoustic-mechanical property than the corrugation. This new kind of lightweight sandwich constructions show promising engineering applications, capable of serving as multi-functional structures with great acoustic and mechanical properties at the same time.