Zhiqiang Wan

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.

Primary Modeling and Analysis of Wing Based on Aeroelastic Optimization

An optimization design method in the preliminary design stage using aeroelastic performance indexes as constraints is proposed to design wing stiffness and build primary model. A beam-frame structure model with a high aspect ratio wing as an example is built. Stiffness distribution of the main beam is designed by engineering estimation method and aeroelastic optimization method to obtain the estimation model and the optimization model. Because of comparative precise, a three-dimensional model of the wing is introduced as the reference model for the comparison of two methods. Static aeroelastic responses are calculated, and the advantage of our method is verified through comparing and analyzing. Effect of aeroelastic performance index on stiffness distribution is also studied under critical load and small deformation, and it indicates that the stiffness of the wing root is very sensitive to the tip vertical displacement constraint.

The Influence of Spar Position on Aeroelastic Optimization of a Large Aircraft Wing with Different Materials

This paper presented studies on structural sizes op timization and arrangement design of a large aircraft wing with different material. Two three-dimensional finite element models of a high-aspect-ratio wing were built that were a met al model and a composite model, and the influence of the front and rear spar position on th e results of the aeroelastic analysis and optimization were studied to improve the wing structure desgin. The most feasible and optimal solutions were effectively obtained by aero elastic optimization. The position parameter of the front spar has a greater influence on the aeroelastic analysis and optimization than the rear spar.