The study of low-frequency ultrawide band gap of conical scatterer phononic crystal

Abstract

Aiming at the problem of vibration damping of low, medium and high frequency noise in the engineering field, an effective phononic crystal structure is proposed in this paper. Firstly, the energy band structure and transmission loss curve of the proposed phononic crystal are calculated using the finite element method, and the first ultra-wide band gap in the frequency range of 122.47-4360.2 Hz is obtained, and the average transmission loss within the band gap reaches 350 dB. Next, the eigenmodes of the phononic crystal are analyzed and the corresponding equivalent spring system is developed. Numerical calculations indicate that the phononic crystal proposed in this paper can perform excellent noise and vibration reduction below 5000 Hz, and it is found that the peripheral silicone rubber connecting plate plays a crucial role in the width of the ultra-wide band gap.