An acoustic metamaterial plate featuring low-frequency broadband vibration damping and sound insulation

Low-frequency vibrations and noise not only disrupt the safe and reliable operation of mechanical equipment, but also have a certain impact on the attention and hearing of the operators. The advent of locally resonant acoustic metamaterials has opened up entirely new avenues for tackling low-frequency vibration and noise issues. Yet, achieving effective control of low-frequency vibration and noise continues to pose significant difficulties. This study presents a new type of locally resonant acoustic metamaterial plate capable of vibration damping and sound insulation below 50 Hz. The structure consists of a main plate and local resonators, which are tightly connected to the main plate through supporting pillars and a framework. Based on Bloch’s theorem, this study calculates the bandgap structure and elucidates the underlying mechanism of bandgap formation. Additionally, the influence of various geometric parameters of the structure on the bandgap characteristics is analyzed. Through numerical simulations and experimental investigations, a comprehensive evaluation of its vibration suppression and sound insulation performance has been conducted. The results indicate that the structure exhibits significant vibration suppression and superior sound insulation performance within the low-frequency bandgap. This research offers new insights and methodologies for the application of locally resonant acoustic metamaterials in the realm of low-frequency vibration suppression and sound insulation.