Multidisciplinary design optimization of a built-up wing structure with tip missile

This study focuses on the influence of a wing tip missile on the design optimization of a wing structure. Finite element models of a realistic built-up wing structure are used to represent stiffness and mass properties. The store location and the effect of the store aerodynamics and mass are the variables included. A multidisciplinary optimization technique is used to compensate\restore the lost aeroelastic performance due to the presence of the store. Missile locations are the only configuration variables addressed in this study besides the structural variables. The built-up wing box structure is optimized with constraints on the static strength and flutter speed. The thickness and the crosssectional areas of the structural elements are the primary variables in the optimization. The aerodynamics of the tip missile has a significant effect on the flutter characteristics. In addition, the flutter behavior of the optimized structure is very sensitive to the tip missile movement along the tip chord. The present results indicate that the effect of the tip missile aft movement must be examined in conjunction with the store aerodynamics. The Automated STRuctural Optimization System, ASTROS, is the primary tool used in this study.