Topological and stress optimizations of silicone layer in space solar arrays

Solar arrays are subjected to drastic thermal cycling in space orbits, which induces stress concentrations or even failure due to thermal expansion mismatches among the GaAs solar cell, aerospace silicone rubber, and substrate. Therefore, it is necessary to determine the mechanical properties of aerospace silicone rubber and design reasonable adhesive structure distribution at the joint to reduce the stress concentration of the solar arrays. Firstly, the viscoelasticity theory was employed, where the mechanical properties and viscoelastic parameters of aerospace silicone rubber are obtained by the Dynamic Mechanical Analysis (DMA) experiment. Then, a three-dimensional finite-deformation thermodynamic model of the Time–temperature superposition process of Thermo-rheological-simple polymers is constructed in Abaqus. Finally, the solid isotropic material with penalization (SIMP) method is utilized to determine the optimal distribution of materials in the design domain by topology optimization, and the microstructure of aerospace silicone rubber topology is reshaped. The results show that the finite element method can accurately predict the stress distribution of the solar arrays in the operating environment. In addition, the topological optimization design aids in reducing stress concentration in the structure and provides a theoretical basis for addressing such problems.