Research On Thermal-structural Analysis Of In-orbit Parabolidal Satellite Antenna

The development of space technology, such as lunar exploration, satellite navigation, and etc., are requiring increasingly higher accuracy and stability for in-orbit satellite antenna. How to improve the in-orbit performing accuracy and stability of large-diameter satellite antenna is a major problem. In this paper we did research on the heat flow, temperature, structural changes, and their influencing factors of parabolic satellite antenna in near-earth orbit, which provides future theoretical references for antenna thermal and structural design. The completed work is as follows:First, the current situation and existing technologies of satellite antenna and the future trend are summarized. External heat flow on antenna surface is systematically studied: 1) Analyze the theory of special thermal radiation and heat flux in near-earth orbit; 2) Use Monte-Carlo method and C++ language to establish parabolic antenna model and beam emission model, and calculate and verify the absorbed heat flow by antenna surface; 3) Analyze the calculation result to study the variation pattern of antenna external heat flow and the affection of surface property.Then, the in-orbit temperature variation of satellite antenna caused by external heat flow changes is studied on the basis of finite element theory. The discrete model of antenna surface is established, and steady and transient temperature field of antenna is analyzed on the basis of Galerkin method. The antenna temperature variation is studied after the simulation by Patran/Nastran software, after which, the antenna surface and material properties are changed in order to find the major influencing factors for antenna temperature variation.Finally, the satellite antenna structural response of spatial thermal load is analyzed. The theoretical formulas of antenna structure variation are derived, and the transient structural field is calculated with Patran/Nastran software, and the antenna thermal deformation and vibration is studied with the simulation result of antenna in-orbit displacement and stress. The affections of antenna material characteristics such as thermal expansion coefficient and elastic modulus, and antenna constraint method are researched after, which will provide references for future antenna design.