Multifunctional strut-plate composite lattice metamaterial for integrated acoustic, energy, and vibration management

In the pursuit of engineering solutions capable of managing persistent hazards such as noise, vibration, and structural impacts, materials that combine sound absorption, vibration damping, and deformation resistance are crucial. Lightweight lattice metamaterials have shown potentiality for these applications. These materials offer design flexibility but typically struggle to simultaneously excel in sound absorption, vibration control, and structural load-bearing. This work introduces a hollow truncated octahedron strut-plate (HTOSP) composite lattice metamaterial, employing additive manufacturing for prototype fabrication. Comprehensive validations were conducted through numerical simulations as well as impedance tube testing, with results aligning well. Adjustments in strut diameters and plate pore sizes enable the HTOSP to achieve impressive mid-high-frequency sound absorption coefficient and half-absorption bandwidth. The structural behaviour of HTOSP under load was explored through numerical simulations and quasi-static compression testing, revealing a high, stable plateau stress and specific energy absorption that peaks and then declines with increasing hollow-strut inner diameters. Furthermore, the HTOSP effectively dampens high-frequency vibrations, achieving –62 dB elastic wave attenuation at 3173 Hz via local resonance. This multifunctional HTOSP lattice metamaterial stands out for its superior performance in sound absorption, vibration control, and mechanical strength, presenting an intriguing paradigm for the design of multifunctional acoustic-mechanical-vibration structures.