Thermally induced deformation of ultra-large truss support membrane structure

Large space structures experience changing thermal environment during orbiting the earth. The resultant temperature gradients induce structural deformations that may downgrade performance of payloads conducting high precision missions and even affect stability of the spacecraft. So, it is extremely important to analyze thermally induced deformation of large space structures for routine operation. In this paper, the ultra-large truss support membrane structure on satellite is characterized and studied. The methodology of thermal quasi-static deformation is formulated and the procedure of thermo-structural analysis is proposed. The thermostructural analysis model with hollow tubes is developed based on finite difference method and finite element method. With heat fluxes from solar radiation, earth radiation, and earth albedo radiation being considered, the temperature distribution filed is obtained from the thermal analysis and then applied to the structural analysis model to calculate quasi-static deformations and root mean square errors with orbital angles. Results show that temperature gradients along circumferential direction of tubes can induce prominent shape error. The proposed method is useful for predicting thermally induced deformation of large space structures and valuable for designing active control systems to compensate for disturbances.