复杂板-腔系统声振耦合机理分析

Analysis of vibro-acoustic coupling theory of a complex plate-cavity model

以敷设多层粘弹性层的复杂弹性板-声腔声振耦合模型为研究对象,结合多层介质声阻抗方法及波数扩展,采用模态展开法推导出点激励作用下耦合系统振动和声场形式解,通过数值计算探索了弹性板参数和粘弹性层参数对弹性板振动和腔内声场的影响规律,并进一步分析了粘弹性层的抑振降噪效果。结果表明:改变弹性板参数对结构振动影响较大;粘弹性层参数对振动和声场影响较显著,其抑振降噪效果主要集中在1000Hz以上中高频段。

In this paper, a research is conducted to model the vibro-acoustic coupling characteristics of a plate-cavity system coated with viscoelastic multilayers. With the application of multi-media acoustic impedance method and wave number expansion,analytical results on sound and vibration of the coupling system induced by a point excitation, is presented on modal expansion method. A detailed research on the physical law of plate vibration and cavity noise induced by the plate and viscoelastic multilayers is carried out via numerical calculation. For further study, the analysis of vibration and noise supreession of the viscoelastic multilayers is also studied. The results show that the changing of the parametres of plate and viscoelastic multilayers may somewhat affect the vibro-acoustic coupling characteristics of plate-cavity system. Otherwise, the vibration and noise reduction induced by acoustic coating mainly works in the middle and high frequency bands in an aqueous medium.