Multiple Re‐Entrant Star‐Shaped Honeycomb with Double Negative Parameters and Bandgap Properties

Achieving bandgaps and double negative properties with single‐phase metamaterial in the low‐frequency range remains a challenge. Currently, acoustic metamaterials with double negative parameters are made of different materials, which can limit their application and design. Herein, a single‐phase multiple re‐entrant star‐shaped honeycomb (MRSSH) is designed and the double negative parameters and bandgaps are simulated. The numerical results show that the MRSSH exhibits three bandgaps and double negative characteristics (negative effective mass density and negative effective modulus) within a certain frequency range. The formation mechanics of bandgaps are investigated by analyzing the vibration modes. Moreover, the effects of geometry parameters such as internal concave angle and re‐entrant on the bandgaps and vibration modes of the MRSSH are investigated. By adjusting the geometry parameters, the dispersion curves and bandgap distribution can be tuned simultaneously. This study provides a new idea for designing a single‐phase lightweight metamaterial that can apply to noised reduction, vibration control, and super‐resolution imaging.