Multi-Objective Optimization Strategies for Aircraft Multi-Disciplinary Design

The goal of this work is the development of a methodology and a computational environment to enable a Pareto frontier analysis for the preliminary design optimization of a wing / horizontal tail / fuselage aircraft configuration. Integrated Multidisciplinary Design Optimization (MDO) is used to solve a multi-objective optimization problem. Two different strategies are taken in consideration to span the design space in the multi-objective process. One is based on a gradient-based algorithm. In this case three different formulations of the Weighed Global Criterion (WGC) method are used, and these functional formulations are analyzed and the concept of a Local Approximation Function is developed to build the Pareto frontier. The other is based on the use of genetic algorithms. The approaches are compared and their capabilities is showed. The compared algorithms use commercial optimization codes and a commercial finite element code to perform the required analyses. Finally, a criterion for selecting an ultimate design solution for the aircraft on the Pareto frontier is also addressed.