Advanced Transport Damage Tolerant GLARE Hybrid Bonded Wing Structure

ABSTRACT: Aurora and UCLA"s Phase I efforts demonstrated the feasibility of the synthesis of advanced hybrid materials, unitized structure, and metallic-composite bonding on the Air Force Next Generation Transport. The X-55 Advanced Composite Cargo Aircraft (ACCA) wing was used to demonstrate the damage tolerance of Glass-Reinforced Aluminum Laminate (GLARE), which is an advanced hybrid material with outstanding fatigue and impact resistance, as well as high static strength. Three-dimensional woven fiberglass Pi-Preforms were used to joint the members together as a unitized structure. Advanced composite components were able to be combined with the metallic structure through the use of the Pi-Preform joints without the galvanization issue associated with composite-metallic bonded structure. A weight savings of 35% was shown for the outboard wing leading edge assembly compared with the existing X-55 ACCA wing leading edge. In Phase II Aurora proposes to develop a structural component, such as the outboard leading edge of the X-55 ACCA Demonstrator Vehicle, to demonstrate the benefits of GLARE unitized structure through manufacturing and testing of a representative article. UCLA will extend their multi-scale constitutive model to predict damage tolerance within the GLARE panels and metallic-composite bonded Pi-Preform joints. BENEFIT: Moving to a unitized GLARE structure on the X-55 ACCA Demonstrator Vehicle will provide a roughly 35% weight reduction in the outboard leading edge due to the improved damage tolerance of GLARE material. Reductions in weight and maintenance costs associated with fatigued and damaged components are possible throughout an aircraft using GLARE material in unitized structural configurations with fiberglass Pi-Preforms. Potential applications include the leading edge of the wing, lower wing skin, cargo doors, and access panels onboard the Air Force Next Generation Transport as well as many other platforms. Aurora envisions applications after demonstration on the X-55 ACCA Demonstrator Vehicle to initially include the Northrop Grumman GlobalHawk and Sikorsky CH-53K S-92 platforms, for which Aurora currently fabricates metallic and composite components. Additionally, the multi-scale constitutive models developed will allow for the publication of new damage tolerant design techniques for use by government and industry.