Thickness optimization of the airplane wing box components by the design of experiments method

Structure optimization in aerospace industries is of particular importance due to the need for light structures to reduce costs and increase flight performance. The main components of an airplane wing consist of spars, ribs and skin. At first, in this research a wing structure with two I-shaped spars, 6 ribs and a shell with specific geometric characteristics is modeled. By choosing aluminum alloy as the material of the structure and using the finite element method, the wing structure has been subjected to static loading and the maximum amount of stress and displacement of the wing box area has been obtained. Then, according to the results of the analysis and the optimization capability, the wing structure has been divided into three parts in order to optimize the thickness of the components along the length of the wing. By defining the thickness of the wing box components in all three parts as factors and stress and weight as the answers to the optimization problem through the method of designing experiments, which in this problem is the static analysis of the structure, the thickness of the components of the wing box area according to the goal of the lowest weight and the highest stress Optimization is allowed. The obtained results indicate that after the optimization, the weight of the wing box has decreased by 46.5%.