Morphology-guided trihybridized metamaterials for dual-band acoustic attenuation and aerodynamic pressure relief

Confined transit hubs require acoustic barriers that reduce broadband noise while preserving ventilation and pressure relief. Here we show a morphology-guided trihybridized acoustic metamaterial that integrates a central micro-perforated panel (MPP), peripheral space-coiling Helmholtz resonators (HRs), and central–peripheral dual-tension membranes. A physics-driven two-stage Time-Varying Acceleration Coefficients Particle Swarm Optimization (TVAC-PSO) strategy keeps the membranes in a stiffness-controlled regime, enabling a deep-subwavelength profile while suppressing parasitic mechanical anti-resonance. The optimized structure provides continuous effective absorption from 250 to 450 Hz and a high-efficiency absorption peak within the 800 to 1500 Hz target range. To satisfy platform screen door (PSD) aerodynamic constraints, four closed unit cells are rearranged into a 2×2 vented supercell with a 5.37% open-area-ratio (OAR) macro-pore. Computational fluid dynamics (CFD) confirms smooth buffering of 500 Pa piston wind, while macro-pore-induced Fano anti-resonance provides 28 dB transmission loss at 950 Hz. Experiments validate the analytical and numerical predictions. Confined transit hubs face challenges in reducing broadband noise while maintaining ventilation and pressure relief. Here, the authors develop an acoustic metamaterial using a nature-inspired design and optimization strategy, achieving effective noise absorption and transmission loss, with significant implications for improving acoustic environments in transit systems.