封闭空间中结构声辐射的有源力控制研究

推导了在初级力源和次级力源共同作用下的弹性结构振动声辐射公式，对封闭空间中的有源结构声控制（ＡＳＡＣ）建立了有源力最优控制模型。模拟实验研究了弹性结构由力源激励所产生的封闭空间声场的特点、有源控制力向量的位置、幅值和次级力源个数的选择等问题。结果表明，弹性结构在力源激励下的封闭声场，是由激励力大小、结构模态和空腔模态间的耦合决定的；对于单模态振动声辐射，应选取振幅最大处作为次级力源的位置，同时优化力的大小；另外，合理选取次级力源个数可有效控制多模态振动声辐射。这些结论为建立封闭空间中结构声辐射有源力控实验系统提供了理论基础。

Study on Active Forces Control of Structure borne Sound in Enclosed Space

The formula of elastic structural sound controlled by both primary force and secondary forces is derived, and the mathematical model of active optimal forces control is presented. The features of enclosed sound field radiated from a vibrating structure, the influences of the position, amplitude and the number of active forces have been investigated by using numerical simulations. It is demonstrated that the enclosed sound space is controlled by the force amplitude and the coupling between the structure and cavity modes, and that the position of maximum vibrating amplitude should be chosen as control force position in single mode vibration. Furthermore, the numbers of active control forces should be properly chosen. The results will lay the foundations of test system of active forces control for structure borne sound in enclose space.