Optimal Design of Unitized Structures with Curvilinear Stiffeners Using Response Surface Methodology

Abstract

Developments in rapid manufacturing techniques have made it easier to manufacture objects with complex shapes. One such technique, Electron Beam Free Form Fabrication (EBF3), has promising features of fabricating panels with curvilinear stiffeners. Preliminary research has shown that panels with curvilinear stiffeners might have a reduced weight than panels with straight stiffeners. Thus, it is essential to have a computational design environment (CDE) to obtain optimum design for curvilinearly stiffened panels. In our earlier study, we have developed one such computer design environment that uses detailed finite element model to obtain optimum design. This design optimization scheme is very computational intensive. Therefore, to make it feasible from an industry point of view, surrogate modeling is required. This paper presents an efficient surrogate model to perform design optimization for panels with curvilinear stiffeners in terms of endpoint coordinates and shape design parameter of curvilinear stiffeners. Developed surrogate model predicts the mass of the panel within an accuracy of ± 1 % as compared to the mass obtained using the high fidelity FEM solver.