Research On Establishment Of Rigid-flexible Coupling Dynamic Model Of Near Earth Satellite

The satellite technology is rapidly developing with the further exploration into space, and the development of which is inseparable from the establishment of the satellite models. Due to the complexity of the satellite structure and particularity of the space environment,the ignorance of the elastic vibration of flexible bodies can greatly affect the stability of the satellite in orbit and cause huge losses as well. Therefore, the elastic vibration of flexible bodies and rigid-flexible coupling should be taken into consideration during the dynamic modeling.The satellite with solar arrays and deployable antenna reflector attached to its central platform was studied in this paper. Firstly, the finite element model of the main structure of the satellite was established, based on the analysis of which and the model reduction technique, a simplified model was established. Secondly, with the consideration of the axial deformation caused by lateral deformation of flexible beam which is dispersed by the mode assumption and the introduction of space gravitation, the first approximate rigid-flexible coupling dynamic equations were established by the use of Lagrange equation. Finally, the traditional zero order approximation dynamic models and the first approximate rigid-flexible coupling dynamic models were simulated to analyze the dynamic characteristics of satellite attitude adjustment. The results showed that the elastic deformation of the flexible attachments can be affected by rigid motion of satellite center platform which also can be affected by the reaction force exerted by flexible attachments. The dynamic response of near earth satellite cannot be correctly described by traditional zero order approximation dynamic model without considering dynamic stiffening. Instead, the first approximate rigid-flexible coupling dynamic model can describe it accurately.The effect of different physical characteristics and structural features on the dynamic characteristics of satellites in orbit was also studied in this paper, which can provide some valuable guidance to the structural optimization design, the control law design as well as the vibration suppression of flexible attachments of the satellite.