Optimal design of the stacking sequences of a corrugated central cylinder in a satellite

This Case Study is to describe an application of a two-level approximation method in optimally determining the stacking sequences of a practical corrugated central cylinder. Being housed in the center of a practical satellite, this cylinder can support many of the structural components and functional devices in the satellite. For the purpose of reducing its mass meanwhile maintaining good mechanical properties, the stacking sequences of this cylinder are to be optimally designed under given constraints in this paper. To address this problem, an optimization model was first established by minimizing the structural mass based on initial lay-ups. With the given lay-ups for multi-parts of this cylinder, the existence of each ply was to be determined in terms of discrete variables. Meanwhile, the ply thicknesses were also treated as continuous variables. The two-level approximation method combined with a genetic algorithm previously proposed by the authors was adopted as the optimization method. According to the practical engineering considerations, multiple optimizations were conducted by starting from different initial lay-ups to search more possible optimization designs. After optimization, it was found that compared with the empirical designs, the mass of the main cylinder could be significantly decreased by obtaining some reasonable stacking sequences.