Modeling and research of hierarchical sandwich honeycomb metamaterials for enhanced broadband sound absorption

This study proposes a novel sandwich hierarchical honeycomb-core acoustic metamaterial (SHHAM) for enhanced broadband sound absorption, addressing the critical challenge of low-frequency noise control under constraints of limited thickness and weight. Drawing inspiration from bio-inspired hierarchical design and series–parallel coupling mechanisms, the SHHAM integrates microperforated panels with a vertex-substituted hexagonal honeycomb core to achieve synergistic multi-modal resonance. Theoretical modeling, numerical simulations, and experimental validation demonstrate that the SHHAM structure exhibits exceptional acoustic performance, with a half-absorption bandwidth ( α > 0.5) of 56% and a quasi-perfect absorption bandwidth ( α > 0.9) of 18% in the 0–4 kHz range. Parametric analyses reveal that key geometric factors—such as perforation diameters, panel thicknesses, and hierarchical scaling factors—enable tunable impedance matching and broadband energy dissipation. The proposed metamaterial offers a promising solution for engineering applications requiring lightweight, high stiffness, and broadband acoustic performance, such as aerospace, transportation, and building acoustics.