SUPERSONIC TRANSPORT WING MINIMUM WEIGHT DESIGN INTEGRATING AERODYNANAMICS AND STRUCTURES

An approach is presented for determining the minimum weight design of aircraft wing models which takes into consideration aerodynamics-struc ture coupling when calculating both zeroth-order information needed fo r analysis and first-order information needed for optimization. When p erforming sensitivity analysis, coupling is accounted for by using a g eneralized sensitivity formulation. The results presented show that th e aeroelastic effects are calculated properly and noticeably reduce co nstraint approximation errors. However, for the particular example sel ected, the error introduced by ignoring aeroelastic effects are not su fficient to significantly affect the convergence of the optimization p rocess. Trade studies are reported that consider different structural materials, internal spar layouts, and panel buckling lengths. For the formulation, model, and materials used in this study, an advanced alum inum material produced the lightest design while satisfying the proble m constraints. Also, shorter panel buckling lengths resulted in lower weights by permitting smaller panel thicknesses and generally, unloadi ng the wing skins and loading the spar caps. Finally, straight spars r equired slightly lower wing weights than angled spars.