Active vibration and noise control by hybrid active acoustic panels

In the present paper a hybrid passive and active treatment for vibration and noise reduction of plate type structures is proposed. The treatment is manufactured as sandwich structure and is called Hybrid Active Acoustic Panel. The passive component is used to reduce the vibration and sound radiation for high frequencies whereas the active part of the system is designed for the low frequency range. By selecting the thickness of the passive damping layer a certain frequency limit is defined, which divides the high and low frequency range. The actuator and sensor layout of the active component is evaluated by using the mode shapes of the low frequency range. According to the evaluated layout a Hybrid Active Acoustic Panel is manufactured and experimentally tested. The experimental results validate the proposed concept.