新型多重开孔式声子晶体低频带隙研究

Study on Low-frequency Band Gaps of New Phononic Crystal With Multi-opening Structure

设计了一种新型多重开孔式局域共振声子晶体结构,结合有限元法计算并分析所设计结构的带隙生成机理和振动特性,并在此基础上进一步分析了带隙影响因素。结果表明,与传统的全连接结构相比,该单元结构质量较轻,且带隙更宽,可在40.8~256.7Hz范围产生带隙,带隙宽度达215.9Hz,占整个低频范围的92.95%。通过进一步优化结构参数,第一带隙起始频率可低至36.1Hz,带宽为174.1Hz。该结构保证较轻质量的同时可实现低频内的较宽带隙,对飞机、潜艇等舱室的低频降噪具有潜在应用前景。

In this paper,a new type of phononic crystal with multi-opening locally resonant structure is designed in this paper.Based on the finite element method,the band gap generation mechanism and vibration characteristics of the designed structure are calculated and analyzed,and the influencing factors of the band gap are further analyzed.It is shown that,compared with the conventional fully connected structure,the proposed unit structure is lighter in weight and can generate much wider band gap in the range of 40.8 Hz to 256.7 Hz,and the band gap width is 215.9 Hz,accounting for 92.95% of the whole low frequency range.By further optimizing the structural parameters,the start frequency of the first bandgap can be as low as 36.1 Hz and the bandwidth is 174.1 Hz.This new type multi-opening locally resonant structure can achieve the purpose of lower in weight and wider band gap in low frequency at the same time,thus has potential application prospects for low-frequency noise reduction of cabins in the aircraft,submarines and the like.