Research On Vibration Control Of Space Membrane Structure

The space membrane structure has high storage ratio and high power-to-mass ratio,which solves the problem of size limitation of the load cabin before entering the orbit.At the same time,it benefits from the huge advantages in terms of the launch cost and application function.The membrane structure has great potential in spacecraft applications,such as reflective antennas,solar power stations and solar sails.However,due to its structural characteristics of low bending stiffness and low damping,attitude adjustment or environmental disturbance may cause long-term low-frequency vibration of the membrane structure,which will affect the reliability of long-term on-orbit operation.In order to avoid the above problems,it is necessary to study the vibration control of the membrane structure.In this thesis,based on the electromechanical coupling characteristics of piezoelectric materials and combined with the finite element method,a four-node rectangular piezoelectric element is derived,and the dynamic equation of a rectangular membrane containing PVDF piezoelectric material is established.The model is reduced by introducing modal coordinates,and then the state space model is obtained.On this basis,considering the influence of controlled modes and residual modes,a PVDF actuator position optimization criterion is constructed based on the controllable Gramian matrix.Taking the rectangular prestressed membrane with four fixed sides as the object,the particle swarm optimization algorithm is used to optimize the position of the actuator under different optimization parameters.Then,considering the model noise,the control and state observation system is designed by the optimal quadratic control theory and Kalman filter.Simulink is used to build a control simulation platform and control simulation.The results show that the vibration of the rectangular membrane under various excitation conditions is effectively suppressed,and compared to uncontrol,the control effect is significant.In addition,through the comparison of the control effect before and after the optimization of the actuator position,it is further verified that the actuator with the optimized position arrangement has better control performance.Finally,based on the research on vibration control of rectangular uniform prestressed membrane,the mechanical properties and vibration control strategies of non-uniform prestressed membrane in complex configurations are explored.A model of the solar sail structural form is established,which is typical application with membrane structures.Abaqus is used to set up two connection ways of solar sail structure.By setting the coefficient of thermal expansion on the cable and applying a temperature field to simulate the prestressed introduction process,the stress distribution and natural frequency of the membrane sail under the prestressed state are calculated,and analyzing the influence of different connection forms on the mechanical properties of the structure.According to the structural characteristics,the active control cable is designed to suppress the vibration of the membrane,and the feedback control law is designed to realize active control.The results show that the active control force generated by the cable can effectively weaken the vibration of the structure and verify the feasibility of the control strategy.