Recipe for Simultaneously Achieving Customizable Sound Absorption and Mechanical Properties in Lattice Structures

Lattice structures with customizable acoustical and mechanical properties show significant promise as practical engineering materials. However, the geometry of traditional lattice structures simultaneously dictates both acoustical and mechanical properties, with alterations in one impacting the other, leaving little room for customization. Herein, leveraging the mechanism of Helmholtz resonators, a general recipe is presented to independently introduce sound absorption and mechanical properties in lattice structures. The sound absorption component is based on a perforated plate, while the mechanical component is based on a truss structure. Through a high-fidelity analytical acoustics model is developed, and finite element analysis outlines the range of properties achievable through the proposed structures. The design encompasses structures with effective absorption, characterized by a resonance peak with coefficient >= 0.7, across almost every frequency in a broad range from 1000 to 5000 Hz, within a range of lattice thicknesses from 21 to 25.5 mm. Also, diverse range of stiffness and strength, and large-strain deformation modes, can be achieved through the implementation of different trusses. Finally, the concept is validated experimentally through 3D-printed samples. This innovative approach allows for the tailored creation of lattice structures that specifically address the acoustical and mechanical requirements in diverse applications. The geometry of traditional lattice structures dictates both acoustical and mechanical properties, limiting designability and customization. Leveraging the principle of Helmholtz resonators, a novel general recipe is introduced to independently introduce sound absorption and mechanical properties in lattice structures. Sound absorption hinges solely on perforated plates, while mechanical properties rely on the immediate truss connections. image