弹性板结构封闭声腔的结构-声耦合特性分析  

Analysis of structural-acoustic coupling of an enclosure surrounded by flexible panel

作　　者：靳国永[1] 杨铁军[1] 刘志刚[1] 李玩幽[1] 季振林[1] 

机构地区：[1]哈尔滨工程大学动力与能源工程学院,哈尔滨150001

出　　处：《声学学报》2007年第2期178-188,共11页Acta Acustica

基　　金：哈尔滨市培养学科后备带头人基金(2004AFXXJ034);哈尔滨工程大学基础研究基金

摘　　要：对弹性板封闭声腔结构-声耦合机制、耦合特性、耦合作用对系统固有频率和模态的影响以及影响结构-声耦合程度的系统物理参数进行了深入的理论与数值仿真分析,并导出了耦合系统固有频率估计式。结果表明：强耦合系统具有较强的闭环反馈系统特征,弱耦合系统具有较强的前馈系统特征；正是由于反馈环节的存在,改变了结构、声腔系统的固有特性和固有频率；发现了规则结构-声腔模态簇耦合的特性；并且发现模态间的簇耦合机制决定了整个结构-声腔系统的耦合作用；任何一簇的结构或声模态仅独立影响其同一簇的声或结构模态以及其耦合后的模态固有频率,而对其它簇的模态没有影响；模态间的簇耦合作用不仅能改变系统固有频率,还会改变耦合系统模态次序和板奇奇模态的模态形状。The structural-acoustic coupling characteristics, mechanisms, effect of structural-acoustic coupling on natural mode and eigenfrecluency of the system are analyzed theoretically and numerically. Formulae for the eigenfrequency of the coupled system are derived. Some new conclusions are obtained. The analysis results demonstrate that the strongly coupled system has obvious closed-loop feedback characteristics, whereas the weakly coupled system has obvious feedforward characteristics, and it is because of the presence of the feedback loop that the natural characteristics and eigenfrecluency are changed. Cluster coupling characteristics between the structural and acoustic modes for the regular cavity and panel system are found, which determine the coupling interaction between the flexible panel and cavity. Any mode in one mode cluster only affects the modes and the modal eigenfrequencies in the same cluster independently. The modal cluster coupling changes not only the eigenfrequencies of the system but also the modal order and structural mode shape.

关 键 词：耦合特性 板结构 弹性板 封闭 强耦合系统 结构模态 固有频率 数值仿真分析 

分 类 号：O421.2[理学—声学]