Design And Optimization Of Piezoelectric Damping System For Vibration Attenuation Of Flexible Cable-Net Structures

In order to passively control the vibrations of the cable net in a large deployable space flexible cable net structure without damping and with microgravity,based on the piezoelectric shunt circuit theory,the author designed a cylindrical piezoelectric damping structure of piezoelectric film.The electrodes of the external circuit can be used in two forms,respectively,to absorb the longitudinal vibration of the string and the lateral vibration of the string.The two kinds of electrodes are distributed in the cylindrical piezoelectric film inside and outside and external resonant shunt circuit of the cylindrical piezoelectric film damping system can be called coil-type piezoelectric film damping system,a number of long strip of electrodes evenly distributed in the cylindrical two side,separately connected resonant shunt circuit of the piezoelectric film damping system known as the long-type piezoelectric thin film damping system.Based on the study of the dynamic characteristics of the large expandable space cable structure and the robustness of the passive damping effect of the resonant shunt circuit,a single string and cross string are taken as the object of study,and the geometric parameters and electrical parameters of the piezoelectric film damping system are designed and optimized.The basic electromechanical coupling model of the piezoelectric thin film damping system and the optimization of the basic theory of the resonant shunt circuit are deduced.The optimal value of the geometrical parameters and the electrical parameters of the piezoelectric thin film damping system are given and verified by numerical method.The frequency domain displacement response,the time domain displacement response and the time domain energy change are analyzed,and the effectiveness of the piezoelectric thin film damping system is verified.The calculation and analysis of theoretical deduction and numerical simulation show that the coil-type piezoelectric thin film damping system has a good effect in suppressing the longitudinal vibration of single string,which can reduce the displacement of the end of string by 92%.In the suppression of single-string lateral vibration should be used long-type piezoelectric film damping structure,vibration suppression effect in general,the first-order vibration suppression effect of 29%,second-order vibration suppression effect of 93%,and there is a certain residual vibration.In the passive control of the vibration of the cross-string,using coil-type connection,the piezoelectric film damping system is applied to the middle of the vertical cable,and achieves a certain control effect – the midpoint amplitude decreased by 63%.The numerical simulation results show that the design method of the piezoelectric film damping system applied to the vibration control of the flexible string is reasonable in its basic shape,polarization direction,geometric parameter and electrical parameter,and the vibration control of flexible string is effective.This study provides a feasible research direction for the vibration control of the spatial cable net structure.