Tunable low-frequency wideband acoustic metamaterials with negative Poisson’s ratio and pre-compression

Traditional acoustic materials typically have fixed acoustic bandgaps (BGs), making them unsuitable for complex vibration environments. In recent years, prestress-controlled acoustic metamaterials have emerged as an effective solution. However, most existing studies fail to meet the requirements for achieving broadband acoustic control in the low-frequency range (below 600 Hz). Therefore, this study introduced a negative Poisson’s ratio structure, utilizing the so-called “trampoline effect,” building on previous research to design a low-frequency, broadband negative Poisson’s ratio structure acoustic metamaterial (NPRS-SC). It utilizes compression, rather than tension, conditions to control BGs. Numerical results indicate that the first low-frequency BG of NPRS-SC ranges from 66.1 to 281.1 Hz, with a lower starting frequency and broader stopband compared to traditional structures. It also demonstrates superior vibration damping performance. Importantly, by introducing compressive prestress conditions, the BG range can be gradually expanded, enhancing vibration damping performance. Specifically, when the strain value λ is set to − 0.03, NPRS-SC’s first low-frequency BG can cover 85% of the frequency range below 600 Hz. Lastly, this study analyzes the influence of NPRS-SC’s geometric parameters on its first low-frequency BG and vibration transmission performance. This research provides essential references and guidance for designing tunable, low-frequency, broadband acoustic metamaterials, offering robust support for future developments in acoustic control technology.