Research on Vibration Isolation Performance of a Metamaterial With Negative Poisson Ratio

Regulation low-frequency noise and vibrations is always a challenging issue in engineering. Metamaterials represent a novel class of materials distinguished by their special mechanical properties. Through meticulous material and structural engineering, regulation of the sound wave transmission can be achieved. A model with a tetragonal negative Poisson ratio is proposed and its transmission properties is thoroughly analyzed. Investigating the impact of structural parameters on band characteristics reveals the regulation mechanism. In the bandgap, the model demonstrates outstanding vibration isolation performance, achieving isolation effects exceeding −100 dB for displacement excitation. Fine-tuning unit sizes and array parameters lead to adjustment of the vibration isolation frequency band, resulting in excellent performance. Specifically, the vibration isolation performance first increases and then decreases as the cone angle θ decreases. It amplifies as the feature length $b$ increases. The relationship between the modals corresponding to certain energy bands and vibration isolation was also studied. The vibration isolation band is offset to a lower frequency by introducing a mass block. Efficient vibration isolation in the frequency range of 80~2000 Hz can be achieved within a thickness of 30 mm, meeting predefined performance standards.