Multi-frequency band gap and active frequency modulation of snowflake-like convex horn ligament structure

In order to realize the vibration reduction and sound insulation within the recognizable frequency of human ear within 20000 Hz, this paper proposes a new type of multi-functional acoustic metamaterial, namely the snowflake-like convex horn ligament structure (SCHLS). Combined with the finite element analysis method and Bloch's theorem, the energy band curve of the SCHLS is calculated, and the sound insulation performance and band gap simulation results are verified through the frequency response function of the finite size structure. The band gap is optimized by introducing elastic-material-wrapped resonators and adjusting the resonator distri-bution and size. At the same time, the innovative use of equal frequency curve, vibration mode and group ve-locity to explain the wave propagation mechanism in depth. Applying large deformations to the novel structures to explore the tuning properties of the structures. The results show that the SCHLS has the characteristics of multi-frequency noise reduction, the optimized structure has better multi-band elastic wave attenuation per-formance, and the active frequency modulation of the structure can further improve its practicability. This research provides a new research idea for realizing multi-frequency noise reduction, analysis of wave propa-gation energy and active frequency modulation.

Automated summary

This paper proposes a new type of multi-functional acoustic metamaterial, the snowflake-like convex horn ligament structure (SCHLS), to achieve vibration reduction and sound insulation within the recognizable frequency of the human ear. Through finite element analysis and Bloch's theorem, the energy band curve of SCHLS is calculated, and the sound insulation performance and band gap simulation results are verified. The introduction of elastic-material-wrapped resonators and adjustment of resonator distribution and size optimize the band gap. The use of equal frequency curve, vibration mode, and group velocity explains the wave propagation mechanism, and large deformations are applied to explore the tuning properties of the structures.