【作者】 郝俊仙；

【导师】 陈南；

【作者基本信息】 东南大学 ， 车辆工程， 2005， 硕士

【摘要】 论文中结合有限元法分析了复杂封闭空间的声模态和双层板结构的模态,建立了有源结构噪声控制模型,从理论上详细的推导了结构声辐射的声腔模态理论和结构模态理论,利用有限元法获得模态数值解来分析声固耦合关系。采用一种新型薄壁单晶体压电致动及传感装置(THUNDER)作为次级力源来控制结构的振动。THUNDER具有卓越的输出位移特性和其固有的柔性,其主动及被动控制特性优于同类的其它压电产品,用它来进行有源结构噪声控制是一个比较理想的选择。论文中对THUNDER的位置进行优化并且合理选择THUNDER的个数。为进一步研究THUNDER致动器及发展有效的控制算法提供了理论基础。通过计算机仿真计算,讨论了以全局时空平均声势能为控制目标函数时声腔声场的变化情况。并分析了空腔中声压的变化与激励频率的关系。搭建了一个双层弹性板中间布置THUNDER驱动器的实验模型,进行了双层弹性板的振动有源自适应滤波LMS控制实验,获得了较好的试验结果;此试验的目的是要验证采用THUNDER驱动器以ANSC方式进行双层壁车厢内噪声模型跟踪匹配控制的可行性。项目研究以车厢内噪声控制为背景,技术使用范围可以推广到所有封闭空间有源噪声控制相关方面。更多还原

【Abstract】 This paper analyzes noise modal of complicated enclosure and structural modal of double panel with FEM, and builds an active structural noise control model. The paper achieves the natural frequencies and modal response and analyzes couple coefficient by the numerical value of acoustic pressure modal and panel modal.The active structural noise within an irregular enclosure is studied. A new analytical modeling method is developed for the reduction of structural vibration using the thin layer composite piezoelectric driver and sensor (THUNDER) piezoelectric actuators. THUNDER possesses many advantages over other conventional piezoelectric actuators. Particularly, its capacity for generating high displacement and its inherent flexibility make it will be an ideal candidate in applications for active structural noise control. In this paper, the position and the number of THUNDER actuators is chosen. The natural frequencies and acoustic modals can be drawn by FEM methods. The control object function is total time averaged acoustical potential energy. The method in this thesis will lay the theoretical foundation of THUNDER actuators.An active structural vibration control test model composed of two flexible plates with THUNDER activator between them is set up, and modal test is done on the model, obtaining its natural frequencies and modal shape. Based on adaptive filtering LMS forward controller。The Thunder’s control on the vibration of the structure is quite effective. This founds theoretical basis for the study of controlling acoustic level in a closed cavity through thunder-based control on the vibration of the structure.The research about active control of structure noise radiation has much prospect in such as automobile, airplane, submarine cabin, etc.更多还原