Abstract: Optimal design of the tank has a significant effect on reducing the weight of a launch vehicle’s structure. In this paper, the key characteristics of a stiffened shell are dentified from the design requirements, focusing on the influence of the internal pressure on the axial compression load-bearing capacity. The computing method of the ultimate load of the stiffened shell, the parametric modeling method and the surrogate modeling technique for optimal design are reviewed. An optimization process applicable to the stiffened shell was developed and applied in the optimization work for the tanks of solid-liquid bundled launch vehicle, so a better weight reduction effect could be achieved.

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