关键词: 星载天线;层合结构;壳单元;非线性变形;动力学特性

Abstract: A dynamic modeling theory for satellite antenna is presented which is subjected to geometric nonlinearity and coupling deformation of flexible reflector undergoing a large overall motion. For the study of the characteristics of the reflector of the multilayer laminated structure, the displacement field description of a point in a three-node shell element is acquired in conjunction with the thickness, transverse bending, lateral bending, and torsional deformations. Therefore, a nonlinear dynamic model of satellite antenna is deduced based on Lagrange’s equations. The complete expression of nonlinear terms of elastic deformation and coupling terms between the multilayer and large deflection are considered in the dynamic equations. Then, satellite antenna dynamics is analyzed between linear model and nonlinear model. The results show that the geometric nonlinear and coupling effects are ignored in the linear model at the initial period. However, as the rotational speed increases, the accuracy of present nonlinear model is suitable for dealing with large deformation problem with rigid-flexible coupling undergoing a large overall motion. Further, the satellite antenna pointing accuracy would be predicted based on the nonlinear model. The above conclusion would have important academic value and engineering significance.

Key words: satellite antenna;laminated structures;shell element;nonlinear deformation;dynamics