Hybrid Tailored Preform for Limited Life Airframe Structures

This Phase II program seeks to develop a low cost high performance keel for the Boeing Unmanned Combat Air Vehicle (UCAV). The preforming concept is based upon a commingled tow, which contains long discontinuous structural filaments allowing the two tostretch in its reinforcement direction. When the CD Tow is woven into a preform, the preform itself can be easily shaped before or during molding. Using this approach complex shaped parts with good mechanical properties can be fabricated at low cost.During the Phase II Program, Pepin Associates will team with Boeing St. Louis to develop the CD Fabric manufacturing process, optimize the forming techniques with CD Preforms, and fabricate three keels for the UCAV. The mechanical performance of the keelswill be determined from coupon and sub element testing. A manufacturing specification will be developed to define each process step and this specification will be used to track costs of the process. The performance, quality and cost of the compositekeels fabricated in Phase II will be compared to the same parameters for other fabrication processes to quantitatively define improvements using the CD Preform approach.