基于谱几何法的板壳-腔耦合系统声振特性研究

Structural-acoustic coupling system, which is consisted with elastic structure and enclosure space, has been widely used in national defense military and civil fields. The research on its vibro-acoustic property is an important fundamental issue. Due to the complexities of the boundary conditions and coupling conditions, the investigation on the coupling characteristics of the plate/shell-cavity is still not sufficient, and the mechanisms of many phenomenons remain to be discovered. This study is focused on plate/shell-cavity coupling system. Sound and vibration transmission characteristics of the coupling system are explored by means of theoretical analysis, numerical simulations and experimental research. Meanwhile, the coupling mechanisms of the system are discovered. The main research contents are as follows: 1) Based on the theories of plate/shell and room acoustics, the mathematical physical models for plate/shell, enclosure, and their coupling system, which can be applicable to arbitrary boundary conditions, are constructed with spectro-geometric method (SGM), respectively; 2) The model experiments are conducted to verify the accuracy and effectiveness of the present vibro-acoustic analysis model; 3) The effects of key system parameters (such as different boundary conditions, coupling conditions, and so on) on the vibroacoustic characteristic are studied. On this basis, the transmission characteristics and coupling mechanisms are analyzed physically. The results would provide a theoretical reference and guidance for noise and vibration control of cabin structures.

由弹性壁面与封闭空间构成的结构-声耦合系统广泛应用于国防军事及民用领域，其声振耦合特性一直是重要的基础性问题。由于边界条件和耦合条件的复杂性，人们对板壳-腔耦合特性的研究仍不够充分，很多未知机理有待探索。本项目拟以板壳-腔耦合系统为研究对象，采用理论分析、数值模拟和实验验证相结合的方法，探索结构-声系统的声振传递特性及耦合机制，主要研究内容包括：1）分别基于板壳理论和室内声学理论，采用谱几何法建立任意边界条件下板壳结构、封闭空腔及其耦合系统的数学物理模型；2）建立相应模型的实验方法，验证本项目所建声振分析模型的正确性；3）研究不同边界条件、耦合条件等系统关键参数对声振耦合特性的影响，从物理本质上分析结构-声系统的声振传递特性及耦合机制。相关研究成果将为舱室类结构的振动与噪声控制提供理论依据和指导。

由弹性壁面与封闭空间构成的结构-声耦合系统广泛应用于国防军事及民用领域，其声振耦合特性一直是重要的基础性问题。由于边界条件和耦合条件的复杂性，人们对板壳-腔耦合特性的研究仍不够充分，很多未知机理有待探索。本项目以板壳-腔耦合系统为研究对象，基于板壳理论和室内声学理论，开展了任意边界条件下板壳结构、封闭空腔及其耦合系统的建模方法研究。采用人工弹簧技术来模拟弹性板壳的任意边界支撑条件。为了克服结构位移容许函数和声压函数在边界上的不连续，以及声-固耦合界面的连续性要求，采用谱几何法对弹性板壳结构与声腔的场分布函数进行展开，结合Rayleigh-Ritz法，分别获得了板壳结构、声腔系统以及耦合系统的特征矩阵方程。通过结构、声固耦合系统的模型实验，验证了本项目构建的理论分析模型的正确性。在声振特性及耦合机理方面，研究了不同边界条件、耦合条件、模型参数等系统关键参数对声振耦合特性的影响，从物理本质上分析结构-声系统的声振传递特性及耦合机制。相关研究成果将为舱室类结构的振动与噪声控制提供理论依据和指导。在项目执行期间，共发表学术论文17篇，其中SCI论文3篇，参加国内外学术交流9人次，研究成果达到了项目申请时的预期目标。