基于粘弹性材料的主被动复合吸声机理研究

Active/passive hybrid control technology is an effective measure in wideband noise control. Early reseach found that not only the active control improves the low-frequency absorption performance of the passive sound-absorbing material, but also the passive sound-absorbing material could at the same time affect the active control. In light of this finding, we propose a research project about sound absorption mechanisms of active/passive hybrid structures. Started from structural dynamics modelling of active/passive hybrid control structures, several fields containing composite structural designing, model parameter reduction, and optimization. Further research will be conducted on, absorption principles of active/passive hybrid structures, and the effects of dynamic mechanical parameters on the active control and the acoustic performance the hybrid structure.Through quantifying the relationship between the dynamic mechanical parameters and acoustic performance, the requirement for appropriate dynamic mechanical parameters will be established. Our research aims at further providing theoretical support for engineering applications of active/passive hybrid control structures with experimental validation both in air and water.

主被动复合控制技术是解决宽频带噪声控制的有效手段，前期研究中发现主动控制能够提高被动吸声材料低频的吸声性能，同时被动吸声材料也影响着主动控制效果，针对上述现象，本项目将开展主被动复合结构吸声机理研究。研究拟以主被动复合吸声结构力学模型为切入点，通过复合结构设计、建模研究、模型降阶及参数优化等方面的研究，旨在阐明主被动复合吸声结构的吸声机理，揭示粘弹性材料力学参数对主动控制及主被动复合结构声学性能的影响，量化主被动复合结构力学参数与声学性能之间的关系，将对主被动复合吸声结构声学性能的要求直接转化为寻求合适的材料动态力学参数，并在空气介质与水介质中对上述理论进行验证，进一步为主被动复合技术的工程化应用提供理论支撑。

提出了一种宽频带吸声的新型主被动复合吸声结构。建立了主动及主被动复合吸声结构的数值模型，阐明了主被动复合结构吸声机理，分析了主被动复合结构声学参数、力学变化对主被动复合吸声结构声学性能的影响，量化了被动材料及主被动复合吸声结构的动态力学参数与声学性能之间的对应关系，并在声管中比较了被动材料和主被动复合吸声结构的性能，结果表明该主被动复合吸声结构能够对单频、白噪声、扫频信号、CW脉冲信号实现有效控制，被动材料在500～1800 Hz频段范围内平均吸声系数约为0.5，而主被动复合结构的平均吸声系数大于0.8。