Lightweight design of a clamp band joint via a constrained sequential approximate optimization method in the irregular design domain

The clamp band joint (CBJ) is a multi-component and complex device for connecting and separating satellites from launch vehicles. In this article, the pre-tightening and connection process are analysed sequentially through an implicit–explicit calculation method. Because of the time-consuming nonlinear analysis, a constrained sequential approximate optimization (CSAO) method in the irregular design domain is proposed for the lightweight optimization design of CBJs. A novel constrained space-filling and non-collapsing sequential sampling method is adopted to address the sampling inefficiency of conventional experimental designs in the irregular domain, while the sequential sampling of exploration and exploitation strategies is balanced for the global and local approximation accuracy. Finally, comparison with the traditional sequential approximate optimization method shows that the proposed method can search the optimum in the feasible region more efficiently. Besides, compared to the initial design, the optimized structure improved the connection stiffness by 56.7% and reduced the weight by 8.3%.