Optimization of ship structure based on zooming finite element analysis with sensitivities

Design optimization process of ship structure having a large opening with zooming finite element method for stress analysis to reduce computational effort is studied. In order for handling the effects of the design variables existing at any part of structure into the zooming region, sensitivities of the design variables are utilized for computing the boundary conditions for zooming finite element analysis. The use of different mesh pattern in the zooming analysis from the global analysis is possible and the effect of mesh refinement on the optimization process is also examined. It is shown that the accuracy of the stress analysis is improved resulting in the more rational optimization of ship structure. Not only displacement but also stress boundary conditions are applied, and the comparison is made to describe the effects of them.