Objectives In order to solve the difficulties of numerous design parameters and time-consuming computation of ship cabin structure optimization, a collaborative optimization method of surrogate model for cabin structure based on sub-model decomposition is proposed.

Methods A grillage was selected at a time, and the sub-model of grillage structure was established based on the finite element model of the current cabin scheme. The surrogate model was constructed for the grillage structure response and optimized based on the sub-model. After the optimization solution of the grillage was obtained, the cabin model was updated, and then the next grillage was optimized. This iteration stopped until one or more rounds of collaborative optimization including all grillages were completed. Finally, a small scale of adjustment of cabin structure size was conducted to obtain the final optimization solution.

Results The optimization result of a ship cabin structure shows that, compared with the cabin structure optimization method based on the dimensionality reduction surrogate model from the point of view of overall optimization, under the equivalent computational cost, the weight in the optimization result of the proposed method is further reduced by 2.86%, and the structural weight is reduced by 4.96% eventually.

Conclusions  The proposed method has better optimization result and better application value on the structure optimization problem of high-dimensional ship hull.