Two-Grade Layout Optimum Design Method For Composite Wing Structure Configuration

Weight is an important performance index for aerospace structure. Weight reduction can not only improve the mobility and endurance capability of aircraft, but also save fuel. As a significant component of airplane structure, wing structure configuration types vary. Among them, stiffened plate structure has been widely used, and its layout optimization design is concerned increasingly in aviation realm.Layout optimization is a difficulty of design. For composite wing configuration, there are many design variables, including the type, the number of reinforced bars, beams and ribs, thickness and stacking sequence, etc, varying from continuous to discrete specie. Together with the various constraints, all of these make layout optimization problem difficult.In this paper a layout optimum design formation for wing configuration is proposed. This formation composed of three steps. Firstly parametric finite element model was set up and approximate model is used to construct the weight function of layout variables and size variables, and then to optimize the weight function to obtain the layout and size of the stiffened panel under given stacking sequence. Secondly the equivalent bending stiffness and GA were employed to deal with the ply stacking sequence optimization, where the requirements of manufacture and etc. were considered. And finally the buckling constrain results given by the layout optimization and stacking sequence optimization were collaboratively optimized and thus the optimal composite stiffened panel was determined.The layout optimization design of the composite stiffened plate and the horizontal stabilizer of certain airplane are studied in this paper using the above method. The method proposed in this paper is proved to be efficient and practical by comparing the final result with the initial solution.