1. Asecond design was developed using a single T300-5208 graphite/epoxy D-spar. The design variable was the percentage of + 45-deg plies in the laminate. The remaining plies of the laminate are understood to be oriented at 0 deg. Constraints on twist deformation, material strength, mass moment of inertia, and dynamic tuning were the same as those used for the metal design. Results shown in Fig. 8 show that the composite design satisfied the required constraints. Further, the minimum weight design had a 0.105-in.thick spar with 20% of the plies oriented at -45 deg, which resulted in blade weight savings of 21.5%. Results-Integrated Aerodynamic Load/Dynamic Optimization
2. On Making Things the Best-Aeronautical Uses of Optimization