Wing and Fuselage Optimization Considering Alternative Material

Abstract

This study is a sensitivity analysis to compare weight benefits for a transport aircraft airframe from potential mechanical property enhancements of CFRP (Carbon Fiber Reinforced Plastic) Laminate and Aluminum Alloy. The computational framework is based on a simplified skin-stringer-frame/rib configuration to model the fuselage and the wings of a generic narrow and wide body jet transport. Simple (Strength of Materials) mechanics were used to predict the stresses in the skin and stringers. Strength allowables and panel buckling equations are used in conjunction with an iterative optimizer to calculate the structural airframe weight. The baseline materials include 7075-T6 Aluminum Alloy and a fictitious intermediate modulus carbon epoxy. For the CFRP material, the optimized weight results show Open Hole compression enhancement produces the most weight benefit. The Fatigue strength is the most sensitive material property for the baseline Aluminum Alloy structure. The results also indicate that the current CFRP laminate minimum gauge limits weight reduction from potential material property enhancements especially on the small jet transport.