基于层合理论的声屏障夹芯板结构振动致声机理研究

Study on Vibration-induced Acoustic Mechanism of Sound Barrier Sandwich Panel Structure Based on Layered Theory

基于层合理论建立声屏障夹芯板的分层计算模型,推导了简谐荷载作用下声屏障夹芯板的振动方程,获得了结构均方振速,求解了声屏障夹芯板的辐射声功率,验证了所提方法的有效性,并进一步探究了声屏障夹芯板结构的振动致声机理。结果表明:声屏障板结构的夹芯层对其模态特性尤其固有频率存在较大的影响,忽略夹芯层的影响而简化为单层均质薄板结构进行声振分析的结果存在较大的差异;声屏障夹芯板结构声辐射响应峰值频率与结构振动峰值频率存在对应关系,并且其声辐射效率不仅与结构振动模态和响应有关,而且与结构声辐射响应也有关,其结构声辐射效率越高,则辐射结构噪声的能力越强。

A layered calculation model was establised for sound barrier sandwich panel based on layered theory and ob-tained the mean square vibration velocity of the structure by vibration equations of sound barrier sandwich panels.The ra-diated sound power of the sound barrier sandwich panel was solved,which verified the feasibility proposed.Finally,the vi-bration-induced acoustic mechanism of the sound barrier sandwich panel was further explored and analyzed.The results show that the sandwich layer of the sound barrier sandwich panel has a significant impact on its modal characteristics,es-pecially its natural frequency.The simulation results obtained by neglecting the effect of the sandwich layer and simplify-ing the structure to a single-layer homogeneous thin plate structure have an obvious discrepancy with the measured val-ues.There is a corresponding relationship between the peak frequencies of sound radiation response and structural vibra-tion of sound barrier sandwich panel.Its sound radiation efficiency is not only related to the structural vibration mode and response,but also to the structural sound radiation response.The ability of radiating structural noise is enhanced with the improving of the structural sound radiation efficiency.