Structural Optimization of Flight Vehicles with Computational-Fluid-Dynamics-Based Maneuver Loads

Amethodologyofperformingstructuraloptimizationwithstaticaeroelasticconsiderationsispresentedforwhich the aerodynamic loads are provided by nonlinear computational aerodynamics schemes. Two main subjects that are studied are the evaluation of airloads on a maneuvering e exible aircraft and their integration with a structural optimization code. A computational aerodynamics code originally developed for solving Euler or Navier ‐Stokes equations for a e xed-shape cone guration is modie ed to incorporate aeroelastic effects. Computational efe ciency is obtained when several aeroelastic trim corrections and optimization runs are performed during the process of e owe eld convergence,such thattheaerodynamicloadsandthestructuraldesign convergesimultaneously.Amodal structuralmodelisusedforelastic-shapeupdates,andatrimcorrectionsalgorithmisusedforvaryingtheincidences and control surface dee ections for obtaining user-dee ned maneuvers. The nonlinear maneuver loads can be combined with linear design cases in a multidisciplinary structural optimization scheme. The method is demonstrated with a wing‐fuselage‐elevator transport aircraft model performing symmetric and antisymmetric maneuvers at Mach 0.85. Thenumber of iterations required for convergenceof thecombined maneuver ‐optimization analysis is typically almost the same as that of regular computational aerodynamics analysis for a e xed-shape cone guration.