Study on band-gap characteristics and formation mechanism of four-ligament chiral elastic metamaterials

Abstract Chiral elastic metamaterials, owing to their exceptional properties distinct from conventional materials and their superior mechanical performance, exhibit significant potential for applications in vibration reduction, noise suppression, energy absorption, and cushioning. To address the challenge of low-frequency vibration control, this paper proposes a dual-component chiral elastic metamaterial structure with four ligament elements. The study explores the bandgap characteristics and elastic wave propagation behavior of this structure within the 1000 Hz frequency range. By analyzing the vibration modes of the unit cell and calculating the group and phase velocities of elastic waves, the physical mechanism underlying bandgap formation is elucidated. The results demonstrate that the proposed four-ligament chiral elastic metamaterial exhibits excellent bandgap properties, with the bandgap covering more than 80.4% of the frequency range below 1000 Hz. This highlights its capability for low-frequency elastic wave control and offers a theoretical reference for the design of novel vibration reduction and noise suppression structures, as well as for low-frequency elastic wave regulation.