FEM Based MDO Model for Entire Ship Structural Optimization

Current sea performance module and structure module in ship Multidisciplinary Design Optimization(MDO) model are based on empirical formulas.In order to improve the precision of the ship MDO model,the sea performance prediction module based on CFD and structural analysis module based on FEM should be established.This paper focuses on the implementation of FEM based structural optimization which is carried out by integrating FEM analysis tools(Ansys) into MDO Framework(iSIGHT).At first,a simple cylinder under pressure is used to demonstrate the integration procedure of iSIGHT and Ansys.Then an entire ship FEM based structural optimization is implemented.The number of the design variables of the FEM based entire ship structural optimization is as many as 202,and has exceeded the upper limit of most optimization algorithms.After several trial calculations and comparisons of the optimization algorithms of iSIGHT,the optimum is obtained,and that is able to establish the FEM based structural analysis module of ship MDO model.