Achieving mechanical-acoustic property integration through hypercube lattice metamaterials

Lattice metamaterials have gained wide applications in aerospace, automobile, and civil engineering due to their superior performances in load bearing, energy absorption, and acoustic attenuation. The increasing lightweight trend has raised new requirements for multifunctional integration for the design of metamaterials. For example, the fuselage of the commercial aircraft carries the loads from the aerodynamic lift, reduces the noise generated by the engine and at the same time attenuates the impact energy during the crash events. However, existing research on lattice materials is mainly focused on the improvement of one specific property, with multifunctional integration not sufficiently investigated. In this paper, a new type of lattice metamaterials called hypercube metamaterials inspired by the four-dimensional Tesseract in science fiction film is proposed. A typical hypercube lattice cell is featured by a nested hybridization composed of an inner simple-cubic (SC) unit and an outer body–cubic (BCC) unit. Three variants of the hypercube metamaterials are presented, i.e., truss-based, plate-based, and truss-plate hybrid variants. Through appropriately adjusting the geometric parameters, multifunctional integration can be achieved by the proposed SC-BCC hypercube metamaterials. The truss-plate hybrid hypercube metamaterial can integrate high energy absorption and strong vibration attenuation utilizing the local resonance mechanism, while the pure plate-based hypercube metamaterial excels in load bearing and sound absorption due to the formation of multiple Helmholtz resonant cavities. This paper aims to provide new pathways for the design of multifunction-integrated lightweight metamaterials with adaptability to different working conditions.