Abstract: In order to solve the problem that the thin walled characteristics are ignored during the process of topology optimization of thin walled cylinder structure in the overall design stage of rocket liked vehicle, which results in the poor processability and stability of the optimized result, an oriented topology optimization method of thin walled cylinder structure considering the stability performance is proposed. Firstly, the finite elements are divided into groups according to the machining direction of thin walled structures, and the optimization design space is recomposed of the basic unit of the elements’ group, which ensures the orientation of the optimization results and conforms to the machining characteristics of thin walled structures. Then, the stability compensated strategy of adding circumferential ribs is introduced to the flow of optimization, and the circumferential ribs are added to the finite element model by modifying the design space, ensuring the optimized structure has better performance of stability. The proposed method has been applied to the structural optimization of rocket interstage, and the simulation results show that the proposed method has good processability and can maintain the stability of the structure under the design load. Compared with the original scheme, the buckling coefficient is increased by 32.21% and the weight of the structure is reduced by 19.05%. The results show that the thin walled characteristics of thin walled structure are fully considered by this method, and the optimized structure has good processability and stability.

Key words: Thin walled cylindrical structure, Topology optimization, Structure optimization, Stability enhancement