Abstract:

A dynamics modeling method is presented for spacecraft with flexible appendages. The dynamics equations are derived taking into account the geometric nonlinearity and coupling deformation terms caused by a large overall motion. And then the nonlinear strain-displacement relations are introduced, and the nonlinear dynamics model of spacecraft is deduced according to the virtual work principle. The complete expressions of geometric nonlinearity and dynamic stiffness terms are considered in the dynamics equations. Spacecraft dynamics are analyzed for linear model and nonlinear model respectively. By comparing these models, both correctness and accuracy of present nonlinear model are verified. Because geometric nonlinearity and dynamic stiffness terms are ignored in the traditional linear model, it is not suitable for dealing with large deformation rigid-flexible problems under the condition of a large overall motion. Furthermore, as the rotational speed increases, efficient and accurate prediction of dynamics behavior for spacecraft with flexible appendages is achieved by using the present nonlinear model. The above conclusion has important academic value and engineering significance.

Key words: Flexible appendages, Spacecraft, Geometric nonlinearity, Thin shell structure, Dynamics