Scantling optimization of FPSO internal turret area structure using RBF model and evolutionary strategy

Abstract

This paper presents the scantling optimization of a typical internal turret area for mooring system of FPSO under full loaded and ballast conditions. The thickness variables are determined by minimizing the weight of the turret area subjected to yeild stress constraints. The Radial Basis Function (RBF) model is built as a surrogate for computationally expensive Finite Element Method (FEM) analysis to improve the efficiency of the optimization. The evolutionary strategy is applied to the optimization. A turret area structure model has been taken as a verification model. The optimization result shows the advantage of achieving optimal thickness distribution of the turret that minimizes the weight under actural engineering constraints.