The Investigate Of Active Structural Acoustic Control

Acoustic radiation emitted by the vibration of thin shell is the main source of noise, and thevibration control of thin shell has been highly concerned in related areas. Passive control method,which exist disadvantage of the heavy equipment, the immense size and the difficulty of setting andmaintenance in various degrees, is the main method of traditional structure-acoustic control. In recentyears, the active noise control technology has been developing rapidly, especially active structureacoustic control method with smart materials, which gathers sensors, actuators and controller withstructure, makes structure have the feature of self-diagnosis, self-learning, self-adaptive andself-healing. And the smart structure is low power consumption, lightweight, flexibility and fastresponse time, and is widely applied to structure acoustic control in low frequency range.In this paper, we adopted piezoelectric ceramic (PZT-5H) as actuator&sensors to investigateactive structure acoustic control. We used piezoelectric solid shell element based on enhancedassumed strain model, acoustical isoparametric element and acoustical infinite element to establish thedynamic equations of mechanics, electricity and acoustic, and used negative-velocity constant gainfeedback strategy to study active structure acoustic control with piezoelectric ceramic (PZT-5H). Inview of enclosed-cavity coupling system, the modal analysis and the active control of time domain inmodel space and frequency range was calculated respectively. For the coupling system in infinite field,the active control of time domain was calculated under harmonic excitation. The numerical computingresults shows that the active structure acoustic control method based on piezoelectric materials hasbetter control effect to structure vibration and acoustic radiation, and is well worth engineeringapplications.