Vibration Control of Stiffened Plates with Embedded Cavities Using Flat Piezoceramic Actuator Devices

Abstract

Noise reduction in the transmission path of aircraft panels is a crucial step of enhanced designs for future aircrafts. Especially the low frequency noise below 500 Hertz is difficult to control by purely passive methods due to principal mass restrictions. Therefore, active structural acoustic control (ASAC) is one of the major approaches in current research to alleviate this frequency gap. This paper presents a preliminary study in this complex topic. A two walled panel with an embedded cavity is investigated, representing the principal characteristics of an airplane panel fuselage segment. The modelling of the mechanical structure and its external excitation in general and the placement of actuators and sensors in particular are major results in the presentation. The transmission path and suitable control laws are based on vibration control and not directly on sound reduction in the first step, to focus on the generation of software tools for the general aspects of simulation and control design. The control objective will be augmented by acoustical energy functions in ongoing work to implement real ASAC in the process chain. Some example calculations finally demonstrate the achievable vibration reduction in the proposed frequency range.