Finite Element Analysis And Vibration Suppression Of Large Solar Array Based On Magneto-rheological Damper

Solar array serves as an important source of energy for spacecraft,providing spacecraft with energy to ensure its proper operation.In order to ensure adequate energy supply,the size of the solar array structure is larger and larger,and its centroid is far away from the body of the spacecraft.Under different excitation,the complex rigid-flexible coupled vibration of the solar array has a non-negligible impact on stability of the spacecraft.In view of the vibration problem of the solar array system caused by impact of particle in the space and unsteady driving of the driving system,it is proposed to reduce the adverse effect caused by the vibration of the solar array through the damping effect of the magneto-rheological damper.The main contents of this thesis are shown as follows:(1)The solar array is analyzed by the finite element method.After reasonable assumption and simplification,the basic solar array finite element model is established.Based on the principle of stability and light weight,the influence of solar array frame,hinge and panel on the fundamental frequency of the system is analyzed.The result shows that the scheme of distributed layout of the material and the laminated structure with honeycomb aluminum as the substrate and composite carbon fiber as upper and lower two layers can effectively improve the fundamental frequency of the solar array under the premise of light weight principle.(2)The dynamic response characteristics of the solar array is analyzed,and the effectiveness of the damper intervention control is verified.The finite element analysis of the determined solar array model is carried out to obtain its low-order natural frequency and model shape.Based on the modal analysis method,the vibration response of the solar array under the impact of space particles is analyzed,and the effectiveness of the damping intervention in reducing the disturbance torque of the solar array root and the windsurfing vibration is verified.For further considering the unstable driving excitation of the solar array,two feasible magneto-rheological damper intervention schemes are proposed.The multi-rigid dynamic model and the rigid-flexible coupling dynamic model of the solar array based on the driving excitation are constructed.The dynamic responses of the kinetic energy and strain energy of the solar array before and after the damper intervention are compared to verify the effectiveness of the intervention program of the MR damper,and a more appropriate damper intervention program is chosen.(3)According to the demand of solar array vibration control,a disc structure of magnetorheological damper is designed and manufactured,then related performance tests are conducted.According to the requirements of the working conditions of the damper,the structural design of the disc magnetorheological damper is carried out from the aspects of structural arrangement of the damper,material selection,and the size of the damper structure is determined by using magnetic circuit analysis.The structural characteristics of the disc damper is analyzed,and design of the structure is simplified after considering the factors such as processing and test,then,the prototype is processed and assembled.Finally,a simple test bench is built to test the working performance of the MR damper.The results show that the maximum damping torque of the damper designed in this paper is more than 8.5N-m,which satisfies the vibration suppression mechanical performance requirements.At the same time,the damping torque changes approximately linearly with the coil current,which means that the damper has good controllability.