Vibration Control Technology Based On Piezoelectric Smart Materials

Large-sized thin-walled structures are widely used in spacecraft,and the working environment is getting worse,which puts forward higher requirements for vibration reduction technology.Piezoelectric materials can realize the conversion of mechanical energy and electrical energy,and have the characteristics of wide frequency response range,fast electromechanical response and good linear behavior,so they are suitable for vibration control.Especially,the Macro Fiber Composite(MFC)has better flexibility,higher piezoelectric constant and electromechanical coupling coefficient.In this paper,MFC piezoelectric patches are used as sensors and actuators,combined with damping circuits and active control methods,and the following research work is carried out on vibration control technology based on piezoelectric smart materials:(1)The interaction relationship between piezoelectric material and matrix material after coupling is obtained.Theoretical analysis and simulation analysis are carried out by the method of multi-physical field coupling modeling,and the physical characteristics,actuator characteristics and sensor characteristics of piezoelectric patches are obtained,and then the state space equation of piezoelectric intelligent structures is derived.(2)Based on shunt damping circuit,the vibration reduction design of the structure is studied.The basic principle of piezoelectric shunt damping circuit is studied,and on the basis of analyzing its impedance characteristics,the circuit parameters are optimized by transfer function method,and the problem of super-large inductance is solved by analog inductance circuit.In order to realize multi-mode vibration control,a shunt damping circuit for multi-mode vibration control is designed.Numerical simulation and experimental verification of the analysis theory and design scheme are carried out,and the results show that the method proposed in this paper can achieve good damping effect.(3)The active vibration control method based on MFC piezoelectric structure is studied.The vibration state of the structure under external force is investigated and described by state space.Then,a Single Input Single Output(SISO)controller and a Multiple Input Multiple Output(MIMO)controller are designed by using the Filtered-x Least Mean Square(Fx LMS)adaptive active control method,and the influence of different control parameters on the control effect is analyzed.On the basis of system identification of the structure,simulation and experimental verification of the control method are carried out,and good control effect is achieved.To sum up,this paper has completed the research based on piezoelectric smart materials,multi-physics field coupling modeling,shunt circuit design,system identification and adaptive active vibration control technology,which provides strong support for improving the adaptability of spacecraft structure to vibration environment.