• Integrating minimal surface geometries into cellular sandwich panels improves low-to-mid frequency noise dissipation. • Increased fluid path convolution achieves high sound absorption typically offered only by significantly thicker designs. • Numerical predictions are experimentally validated using additive manufacturing and impedance tube testing. • Proposed architecture provides the flexibility to target a broad frequency range within a compact and lightweight structural profile. A novel hybrid metamaterial is proposed for enhanced low-to-mid frequency sound absorption. Primitive, gyroid, and diamond triply periodic minimal surface (TPMS) lattices are reverse engineered to reduce computational cost. These are integrated with a microperforated panel and a 2D re-entrant auxetic structure to form a mechanically stable Helmholtz resonator, overcoming limitations of mono-TPMS and MPP-TPMS designs confined to higher frequencies. COMSOL predicted sound absorption coefficient (SAC) were validated using impedance tube measurements on samples fabricated via digital light processing (DLP). The diamond TPMS hybrid showed the best performance, achieving an average SAC of 0.57 across 50–1800 Hz, exceeding 0.5 at 825 Hz and reaching unity at 1200 Hz with only 20 mm thickness and 10 g weight. Tunability was also demonstrated: increasing the height to 50 mm yielded an average SAC of 0.79, exceeding 0.5 at 375 Hz and reaching unity at 850 Hz. These results confirm that the proposed TPMS-based hybrid metamaterial enables efficient, broadband acoustic absorption in the low-to-mid frequency range, significantly improving the functional applicability and design flexibility of TPMS architectures for advanced noise control applications in engineering systems.
Naveed et al. (Fri,) studied this question.