To obtain a reliable pressure hull structure, the 6σ design was introduced into the optimization of pressure hull. The influences of the uncertainty of material and dimension error when processing were fully taken into consideration. Based on the MDO platform iSIGHT, a reliable optimal plan involving 6σ was obtained. In order to reduce the calculation expense, a sufficiently accurate RBF model was used to replace the simulation program ANSYS when iterating, which not only ensured the accuracy but also saves the calculating cost.

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