Study On Vibration And Noise Control For Aircraft Panel Structure Based On Piezoelectric Technique

With the development of high-performance military aircrafts and power devices, theincreasingly severe vibration fatigue and acoustic fatigue issues of aircraft are brought toresearchers and engineers. Such as, for F-18aircraft, fatigue failure is caused by the vertical tailbuffet when it flies at high attack-angle. Furthermore, civil aircraft airworthiness certificationrequirements are more stringent, and aircraft cabin comfort requirements are more continuouslyincreasing, e.g. acoustic and vibration airworthiness test and verification of ARJ regionalaircraft were required before its first flight. Therefore, how to control noise and vibrationeffectively becomes an urgent task for modern aircraft.Recently, more and more researchers study vibration and noise control for differentstructures using active/semi-active control methods with the development of control technique.Meanwhile, with the piezoelectric materials developed, the study on structure vibration controlusing piezoelectric technique has become the leading direction. In the manuscript, thetheoretical analysis and experimental researches on controlling the vibration and noise oftypical aircraft structure based on the piezoelectric technique are proposed. The contents of thispaper are organized as follows:(1) The active and semi-active control theories and their application in structural vibrationand noise are studied.In semi-active control method, piezoelectric shut damping means are concentrated,including Synchronized Switch Damping on Short circuit (SSDS), Synchronized SwitchDamping on Inductor (SSDI) and Synchronized Switch Damping on Voltage source (SSDV).Piezoelectric control circuits, formulations of the control system and energy relationships ofthese SSD techniques are obtained and the vibration control methods are provided for typicalshell structure of aircraft.In active control method, Filtered-X LMS algorithm and identification method ofsecondary path of the vibration controller is designed. The vibration controller algorithm is builtfor aircraft typical shell structure excited by vibration and noise loads.(2) Vibration and noise control system model for panel structure excited by vibration andnoise loads is established with piezoelectric shut damping circuit. The equations of strain energyand kinetic energy for panel structure and the piezoelectric patches are obtained. Moreover, thesurface impedance and absorption coefficient of the panel structure are obtained. Thetheoretical basis using piezoelectric technique is provided for aircraft structural vibration andnoise reduction.(3) The different layouts of piezoelectric patches using piezoelectric shut damping theoryare designed for controlling the vibration of plate, stiffened panel and aircraft frame structures.The influence of piezoelectric patches layouts on structural vibration control is obtained. Thus,the piezoelectric patches layout method is given for aircraft typical shell structure on how to reduce the vibration and noise.(4) Synchronized Switch Damping on Inductor circuit is designed. Semi-activepiezoelectric vibration control experiment for aircraft frame structure is carried out under noiseloads. The results show that structural vibration response can be suppressed up to25%.(5) Based on piezoelectric active control technique and Filtered-X LMS adaptive controlmethod, the experimental study on vibration and noise control is performed for a cabin segmentstructure of aircraft fuselage. The results show that the structural vibration response can bereduced by63%. Meanwhile, the noise level can be reduced by10.6dB.The innovative issues of the thesis can be concluded as follows:(1) The structure vibration control is studied using piezoelectric shut damping method foraircraft frame. The effects of the layouts of piezoelectric patches on the vibration control areachieved.(2) The vibration control experiments are firstly performed using SSDI piezoelectric semi-active vibration control method for aircraft frame structure excited by noise loads. The resultsof experiment and simulation have a good agreement. The effectiveness and feasibility ofSynchronized Switch Damping on Inductor method are verified for aircraft typical shellstructural vibration and noise control.(3) In the experiment of controlling the vibration and noise for the shell of aircraft fuselage,the Filtered-X LMS adaptive control method is firstly introduced. The experimental resultsshow the new provided method mentioned above has a good effect on controlling the vibrationand noise for the shell of aircraft fuselage.The thesis is supported by Aviation Science Fund ("The noise control based onpiezoelectric technique for typical shell structure of aircraft", No.20091523010).