Coupling dynamic performance analysis for a satellite antenna system with space thermal load

The rigid-flexible dynamics of a satellite antenna system considering thermal load was studied under space environment. According to geometric characteristics of a parabolic antenna reflector, the temperature function in one element along its thickness direction was built for shell structures, and the finite element forms for heat conduction equations were derived. Then, the coupling terms related to strain energy were introduced. By using Lagrange's equations, the rigid-flexible coupling dynamic model of a freely floating satellite antenna was deduced under the large-scale motions. Therefore, the influence of the heat effect on the coupling performance of the satellite antenna system was studied numerically. The result showed that the temperature gradient induces vibration of flexible reflector to produce its elastic deformation; furthermore, its elastic vibration is aggravated to lead to deviations of satellite base attitude and disturbances of antenna pointing; thus, the satellite antenna pointing accuracy is seriously affected. The above conclusions had an important academic value and engineering significance.