Methods For Modular Modeling Of Flexible Spacecraft Dynamics And Finite Element Model Updating

As the most widely used human spacecraft, engineering of satellite is increasing rapid and its quick design, system modeling, as well as simulation have become an important direction of satellite dynamics modeling. But the satellite system is complex, both in design and development process, following with subsystems coupling which has a direct impact on the quick design of satellite system. In this case, design of satellite structural and control systems through modular modeling is important to quick modeling of satellite system. This paper focuses on research of modular methods for mechanical modeling and finite element model updating of spacecrafts with flexible appendages. The main contents are listed as below:First of all, methods for modular modeling of satellite with no appendage and with a rigid appendage are addressed. Satellite model which has no rigid appendage is also other satellites’ hub. At the beginning, this paper builds its dynamics module model which lies the foundation for future research. The modular model of satellite with an idealized rigid appendage is set up as well. Then the central root’s module, the appendage’s dynamical module, the installation vector’s module, the coordinates conversion’s module are built, contributing to achieve rigid satellite’s modular modeling and simulating.Secondly, methods for modular modeling of satellite with single flexible appendage are issued in this part. After using the hybrid coordinate method and state-space method to derive kinetic equations, the flexible appendage’s module and the flexible-rigid coupling module are built. Based on methods which have been mentioned before, the modular modeling method of the satellite with star-like flexible appendages is completed.The third part states methods for modular modeling of satellite with chain-like flexible appendages. Establish the midbody module and the terminal module in the chainlike flexible systems by using C-B function and state space method, in order to define this satellite modular modeling method.Finally, research on methods of the finite element dynamic model updating are drawn. Accurate finite element model can provide precisely kinetic parameters for the modular modeling method. To obtain accurate finite element model, the author did specimens modal testing on the ground, using ground modal test data to correct the finite element model of the specimen, through adjusting the relevant parameters and material parameters of the unit to obtain a more accurate finite element model.