Vibration Control By Using Negative Capacitance Shunting Of Piezoelectric Patch And The Application In Space Rack

In the process of launching the rocket to a predetermined orbit,the shock and bandwidth random excitation from the rocket will be amplified step by step when transferred to the space rack,which may lead to irreversible damage to the space rack and the scientific instruments carried inside.Aimed at the vibration control of the space rack,a piezoelectric shunt method is proposed in this paper to get a broadband vibration attenuation performance of the host structure.The research is carried out according to the following partsDesign of negative capacitance circuit.Based on the negative resistance circuit,a negative capacitance shunt is designed,and the characteristics are discussed.A dynamic model of a single degree of freedom system coupled with piezoelectricity and negative capacitance shunt is established,and the numerical simulation is carried out to discuss the stiffness,natural frequency and amplitude of the coupled systemA study of vibration control of linear cantilever beam is followed,which is the development of the single degree of freedom system.According to the classical Euler-Bernoulli beam theory and Galerkin approximation theory,the vibration control equation of the cantilever beam structure excited by the based is established.Furthermore,the dynamic model of the linear cantilever beam coupled with a PZT patch is established.A negative capacitance shunted with PZT is designed for the vibration attenuation of multi-mode of the cantilever beam.Also,numerical simulation is carried out.Vibrat ion control of nonlinear cantilever beam structure is discussed followed the linear one The magnetic field and magnetic distribution expression of the magnetic medium are obtained to construct the nonlinear force based on the molecular current model.The vibration control equation of the nonlinear cantilever beam with concentrated mass at the free end is established,the hannonic balance method is applied to solve the response of the first mode of the nonlinear cantilever beam under the basic excitation,the piezoelectric shunt with negative capacitance is also used to control the vibration of the structure,and the theory is also numerically simulated.The final part of the research is vibration control of space rack by using piezoelectric shunt.Patran and Nastran are used to model the space rack by finite element method.Freedom condense method is introduced to reduce the calculation work of the model,the dynamic model of the coupled system of the piezoelectric shunt and the space rack is established,and the numerical simulation is also conducted to analyze the vibration of the coupled system.Through the study of vibration control of linear and nonlinear systems by using negative capacitance shunting of piezoelectric patch,the work presents a method to establish the dynamic equation of the coupled system between host structure and PZT patches shunted with negative capacitance,which can be used in the vibration control of large-scale complicated structures.Through the work above,a novel way of a broadband vibration control technology for space rack is realized.