Abstract: A robust aeroelastic optimization method which is based on the genetic algorithm and takes into consideration the uncertainties in structure and trim is presented for an air vehicle with multiple control surfaces.This method is applied to the robust design of structure and gear ratios between the control surfaces for a complicated aircraft with a low-aspect-ratio and an active aeroelastic wing(AAW). The uncertain variation of design variables is estimated with a non-probability method. Robust optimization is formulated in the form of a single objective by introducing an additional constraint which reflects the relative change of objective. The concurrent optimization design of the structure and gear ratios is implemented in the case of critical load conditions. The objective is to minimize the structural mass subject to the robust constraints of deflection angles of control surfaces, hinge moments, loads acting on the wing root and critical flutter speed. A comparison is also performed between the robust method and the traditional method in which the robust requirements are not considered, and the validity of the robust method is demonstrated. The result shows that the robust optimization solution is more resistant to jamming in the face of the perturbation of design variables of structure and gear ratios. However, a mass increment has to be paid for satisfying the robust requirements.

Key words: multiple control surfaces, robust optimization design, active aeroelastic wing, genetic algorithm, flutter, flight loads