Topology optimization of parts in a satellite structure under stress and frequency constraints

At the early design stage of a satellite structure, it is desirable to consider topology optimization of some key parts as well as sizing parameters. Finite element model of the satellite is established according to the original design In order to take both kinds of design parameters into account, a two-stage optimization procedure is implemented by taking minimum weight as the design objective. First, topology optimizations based on SIMP concept are carried out under frequency constraints and stress constraints, respectively, in which two-level multipoint approximation algorithm and full-stress method are applied as the optimizer and optimality criteria. Topology optimization results are obtained with shell elements, which are then transformed into frame structure with beam elements. Second, taking the cross-sectional dimensions of the obtained beams and other size parameters as design variables, the structure is further optimized. Both stages are implemented through a new developed module by PCL (Patran Command Language) on the base of MSC. Patran/Nastran. Through the optimization, reasonable topology of the key parts is obtained, the satellite's static and dynamic performance is improved while its weight is reduced, which provides reference to the real structure design.