Active Structural Noise Control By Using THUNDER Actuators

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.