Design and numerical validation of quasi-zero-stiffness metamaterials for very low-frequency band gaps

Noise pollution has become a significant global problem in recent years. Unfortunately, conventional acoustic materials cannot offer substantial improvements in noise reduction. However, acoustic metamaterials are providing new solutions for controlling sound waves, and have huge potential for mitigating noise propagation in particular. Recently, owing to the rapid development of acoustic metamaterials, metamaterials for acoustic noise reduction have drawn the attention of researchers worldwide. These metamaterials are often both light and compact, and are excellent at reducing low‐frequency noise, which is difficult to control with conventional acoustic materials. Recent progress has illustrated that acoustic metamaterials effectively control sound waves, and optimizing their structure can enable functionality based on new physical phenomena. This review introduces the development of acoustic metamaterials, and summarizes the basic classification, underlying physical mechanism, application scenarios, and emerging research trends for both passive and active noise‐reduction metamaterials. Focusing on noise reduction, the shortcomings of current technologies are discussed, and future development trends are predicted. As our knowledge in this area continues to expand, it is expected that acoustic metamaterials will continue to improve and find more practical applications in emerging fields in the future.

Acoustic Metamaterials for Noise Reduction: A Review

Based on auxetic foam: A novel type of seismic metamaterial for Lamb waves

Wave attenuation in elastic metamaterial thick plates: Analytical, numerical and experimental investigations

Numerical and experimental study of a sandwich-like metamaterial plate for vibration suppression

Broadband locally resonant metamaterial sandwich plate for improved noise insulation in the coincidence region

Suppression of the vibration and sound radiation of a sandwich plate via periodic design

Locally resonant metamaterial curved double wall to improve sound insulation at the ring frequency and mass-spring-mass resonance

Locally resonant metamaterial flat panels have proved to potentially exhibit extraordinary sound transmission loss properties when the resonance frequency of the resonators is tuned to the coincidence frequency region. Whether this technique is also effective to address the ring frequency effect for curved panels is investigated in this paper. For this purpose, a cylindrical shell, as a representation of curved panels, is studied from a theoretical and numerical point of view, with a specific focus on the transmission loss behaviour around the ring frequency region when the shell is mounted with local resonators. The influence from the resonators is presented and compared with that for a flat panel. An inverse effect of the resonators is observed on the sound transmission loss between the metamaterial cylindrical shell and the metamaterial flat panel when the resonance frequency of the resonators is tuned to be below or above the ring or coincidence frequency, respectively. Rather than the extraordinary improvement observed for the metamaterial flat panel, tuning such conventional resonators to the ring frequency of curved panels generates two side dips despite a sharp improvement at the ring frequency itself. This phenomenon is explained from an effective impedance point of view developed in this paper. The approach proposed and the conclusions provided may subsequently allow for the design of suitable resonators in order to resolve the ring frequency effect for curved panels.

Investigation of the sound transmission through a locally resonant metamaterial cylindrical shell in the ring frequency region

Molecular Dynamics Study on Friction of the Iron-Aluminum Alloy

Zibo Liu

Papers

Broadband locally resonant metamaterial sandwich plate for improved noise insulation in the coincidence region

Suppression of the vibration and sound radiation of a sandwich plate via periodic design

Locally resonant metamaterial curved double wall to improve sound insulation at the ring frequency and mass-spring-mass resonance

Investigation of the sound transmission through a locally resonant metamaterial cylindrical shell in the ring frequency region

Molecular Dynamics Study on Friction of the Iron-Aluminum Alloy