Suppression of low-frequency ultrasound broadband vibration using star-shaped single-phase metamaterials

In order to suppress the low-frequency ultrasound vibration in the broadband range of 20 kHz–100 kHz, this paper proposes and discusses an acoustic metamaterial with low-frequency ultrasound vibration attenuation properties, which is configured by hybrid arc and sharp-angle convergent star-shaped lattices. The effect of the dispersion relation and the bandgap characteristic for the scatterers in star-shaped are simulated and analyzed. The target bandgap width is extended by optimizing the geometry parameters of arc and sharp-angle convergent lattices. The proposed metamaterial configured by optimized hybrid lattices exhibits remarkable broad bandgap characteristics by bandgap complementarity, and the simulation results verify a 99 % vibration attenuation amplitude can be obtained in the frequency of 20 kHz–100 kHz. After the fabrication of the proposed hybrid configurational star-shaped metamaterial by 3D printing technique, the transmission loss experiments are performed, and the experimental results indicate that the fabricated metamaterial has the characteristics of broadband vibration attenuation and an amplitude greater than 85 % attenuation for the target frequency. These results demonstrate that the hybrid configurational star-shaped metamaterials can effectively widen the bandgap and realize high efficiency attenuation, which has capability for the vibration attenuation in the application of high-precise equipment.