Band Gap Mechanism and Design of a New Type of Six-Ligament Chiral Structure

Achieving low-frequency and wide band gaps with a simple and small structure can be a challenging task. In this paper, a new type of six-ligament chiral structure with simple geometric parameters and smaller geometric dimensions is designed. The side length of the chiral unit cell is only 20 mm. The proposed structure and the design idea it embodies may be of assistance to deal with the challenges mentioned above. A numerical simulation is performed to analyze the relationship between the geometric parameters and band gap characteristics of the structure. Based on this relationship, a geometrically optimized structure is proposed and the simulation results show it has better band gap characteristics which can achieve low-frequency and wide band gaps. Moreover, frequency response analysis is used to verify the accuracy of the simulation. Finally, the band gap mechanism is analyzed by analyzing the mode diagrams of the structure.