Ground Structure Approaches for the Evolutionary Optimization of Aircraft Wing Structures

Abstract

Aircraft wings have seen very few changes in the topological arrangement of the internal structures during the past decades. However, the traditional topology consisting of longitudinal spars and transverse ribs has not been conclusively shown to be the optimal. The purpose of this study is to develop a tool to explore the space of alternative internal structure topologies. We consider a pair of two-step optimization methods. First, a large set of potential structural members, i.e. a ground structure, is built inside the outer mold line of the wing. Second, an evolutionary optimization method is applied to search for the optimal subset of structural members. Two methods are used: a genetic algorithm (GA) and an evolutionary structural optimization (ESO) heuristic. The objective in both cases is to minimize the structural mass of the wing subject to stress and buckling constraints, which are evaluated by automated finite element analysis. The methods are applied to the structural design of the 3D printed wing of a small unmanned aerial vehicle (sUAV) and benchmarked against manually designed internal structures.