Design Optimization of a Ship Hull Block Based on Finite Element Analysis

Optimization techniques for shipbuilding have been developed to design large-scaled commercial vessels based on classification rules and analytical data, but most of the target model in the past were restricted to the mid-ship section design in the preliminary design stage. By contrast, preceding researches about the design optimization of detailed structures are relatively rare since narrow information has been provided as the design guide for such structures. In this study, the minimum weight design of a ship hull block was carried out based on the finite element analysis. The target model for design optimization is a stiffened deck block of LNG carrier for upholding a main boiler. The weight of a ship hull block and the main dimensions of structural members are chosen as an objective function and design variables, respectively. An optimization algorithm was adopted to escape the local minima and reduce CPU time in analysis procedure, and finite element analysis was performed to determine the constraint parameters at each iteration step in optimization loop. Optimization results were compared with an existing ship, and the effects of optimum design were examined from various points of view.