Multifunctional Sound-Absorbing Metamaterials Integrating Acoustic and Mechanical Properties

Low-frequency noise has always been a challenging issue in the field of noise control. To effectively absorb low-frequency noise, various resonant absorption meta-materials have been designed. However, previous resonant absorption meta-materials have focused too much on acoustic performance while neglecting mechanical properties, which has limited their applications. In this work, a multi-functional meta-materials that simultaneously achieves low-frequency sound absorption and excellent compressive strength is proposed, called the acoustic absorption-compressive resistance meta-materials (AA-CR). By extending and folding the embedded square tube of the Helmholtz resonator to the bottom and perforating the sides of the tube, the square tube can achieve multiple functions including sound energy dissipation and enhanced compressive strength. The acoustic performance can be adjusted by changing the position and size of the perforations, increasing the design freedom. Additionally, because of the support function of the square tubes, the AA-CR is expected to have superior compressive resistance compared to Helmholtz resonators. Based on this, a broadband absorption structure composed of 9 units is proposed, which can achieve broadband sound absorption over a wide frequency range from 314 to 541 Hz with a thickness of only 42 mm. This work contributes to the development of multi-functional sound-absorbing meta-materials.