2341. Advanced Lightweight Aircraft Fuselage Structure – Phase I

Paper

Abstract

Advanced structural technologies are key to the Joint Strike Fighter (JSF) aircraft’s affordability, effectiveness, and risk. Early consideration of improved designs and processes reduces risk and increases performance. Identifying optimum load paths early helps develop manufacturing techniques and mature the configuration. Advanced composite manufacturing techniques such as resin transfer molding (RTM), resin film infusion (RFI), fiber placement, and braiding are important affordability initiatives. Co-curing, co-bonding, and advanced fastening processes must also be considered to reduce both weight and cost. ALAFS (Advanced Lightweight Aircraft Fuselage Structure) is a JAST (Joint Advanced Strike Technology) Structures and Materials Technology Maturation program. ALAFS addresses many of the structures and materials issues facing JSF through demonstrations of emerging and new technologies via the design, fabrication, and test of full-scale center fuselage/inner wing hardware. The F/A-18E/F center fuselage and inner wing were selected as the ALAFS baseline to provide a well-defined cost and weight database as well as a complete, customer-approved set of design, manufacturing, and support requirements. This ensures the ALAFS designs and manufacturing methods are suitable to production and fleet environments. ALAFS Phase I utilizes an innovative approach to structural arrangement, concept development and selection. Instead of ”Brainstorming” several specific arrangements, the design team identified the major influences of cost and weight on an integrated center fuselage/inner wing structure. For each of those ”design factors”, two concepts were created. the resulting design space covers one hundred twenty-eight potential configurations – too many to be evaluated during ALAFS Phase I. Therefore, the team applied the Taguchi design-of-experiments approach to represent the entire design space using only eight concepts. Finite Element Model Weight Analysis (FEMWTS) techniques were used extensively to shorten the time required to estimate the weight of each of the eight Taguchi concepts. From these development and performance evaluations, the team was able to identify which design factors truly influence cost and weight, and which combinations of concepts provides the lowest cost and weight.