Robust Design Optimization of Flexible Backswept Wings with Structural Uncertainties

ROBUST design method, which was originally presented by Taguchi [1] to improve product quality so that structural performances were insensitive to the potential parameter variations, have been gradually applied to the designs of engineering structures [2–4]. However, the structures presented in these robust designs are relatively simple, and the aeroelastic problems that are critical in the design of modern aircraft are not primarily involved. In recent years, some efforts have been contributed to the consideration of uncertainties in aeroelastic design [5–9]; meanwhile, a few methods such as -k method [7], polynomial chaos method [9], and response surface method [10] have been developed to advance robust aeroelastic analysis and enhance aeroelastic stability. Nevertheless, the uncertainties of structural design variables in robust aeroelastic optimization are not taken into account in most studies. The objective of this research is to develop a method for robust aeroelastic optimization with structural parameter uncertainties, based on a genetic algorithm. The current work focuses on introducing the robust aeroelastic constraints into the process of optimization, and a deterministic estimate is used to account for parameter variations. Comparing with the traditional optimization method, the capability of robust method is then demonstrated by its application to the complicated structural designs of flexible composite high-aspectratio wings with various backswept angles.