Title: Tailorable Universal Feedstock for Forming (TUFF): Overview and Performance

Authors: Shridhar Yarlagadda, Joseph Deitzel, Dirk Heider, John Tierney, and John W. Gillespie Jr.

DOI: 10.33599/nasampe/s.19.1605

Abstract: Under the Defense Advanced Research Projects Agency (DARPA) Tailorable Feedstock for Forming (TFF) program, the University of Delaware - Center for Composite Materials (UD-CCM) led-team proposed to develop a manufacturing process and pilot facility to produce novel discontinuous carbon fiber composite feedstock for forming, with the potential to revolutionize the use of composite materials, as a cost-effective replacement for small complex geometry metal parts (<2 sq. m.). The TuFF (Tailored Universal Feedstock for Forming) feedstock consists of a highly aligned discontinuous carbon fiber preform in thin-ply format, which can be combined with thermoplastic or thermoset resins for prepreg, or used in dry form for infusion-based manufacturing processes. A patent-pending discontinuous fiber alignment and preforming process has been developed and implemented in a pilot facility at UD-CCM. The alignment process is fiber agnostic and TuFF preforms have been manufactured with aerospace grade fiber (IM7, T800), pitch carbon fiber, and recycled carbon fiber. Using discontinuous IM7 carbon fiber and Polyetherimide (PEI) thermoplastic resin, TuFF composites with aerospace quality requirements (<1% voids, up to 63% fiber volume fraction) have demonstrated 100% translation of fiber stiffness and strength in tension, and >40% bi-axial in-plane strain capability during forming. The in-plane stretchability of TuFF preforms enables conformability of simple planar preforms to complex geometries, eliminating the need for darting and complex ply patterns while minimizing associated scrap during composite layup. Closed-loop recycling and reuse strategies are possible for the first time with the ability to reuse fiber and preform scrap, prepreg scrap and recycled composite parts.

References: 1. Such et al., Aligned discontinuous fiber composites: a short history. J. of Multifunctional Composites, 2014. 2. Géraldine Oliveux, Luke O. Dandy, Gary A. Leeke, Current status of recycling of fibre reinforced polymers: Review of technologies, reuse and resulting properties, Progress in Materials Science, Volume 72, 2015, Pages 61-99 3. Granta CES Selector 2018 (Granta Design Limited, 2018). 4. H. Yu, K.D. Potter, M.R. Wisnom, A novel manufacturing method for aligned discontinuous fibre composites (High Performance-Discontinuous Fibre method), Composites Part A: Applied Science and Manufacturing, Volume 65, 2014, Pages 175-185 5. Šimáček, P., and S. G. Advani. ""A micromechanics model to predict extensional viscosity of aligned long discontinuous fiber suspensions."" International Journal of Material Forming (2018): 1-15. 6. Dirk Heider, John Tierney, Mohamed A. Henchir, Verena Gargitter, Shridhar Yarlagadda, John W. Gillespie, Jr., Jessica Sun, Jennifer M. Sietins, Dan Knorr, “Microstructural Evaluation of Aligned, Short Fiber TuFF Material,” SAMPE Conference Proceedings. Charlotte, NC, May 20-23, 2019. 7. https://www.niar.wichita.edu/coe/ncamp_documents/Hexcel%208552/CAM-RP-2009-015%20Rev%20A%20April%2022%202011%20Hexcel%208552%20IM7%20Uni%20Data%20Report.pdf 8. Shridhar Yarlagadda, Suresh Advani, Joseph Deitzel, Dirk Heider, Dan Molligan, David Roseman, Pavel Simacek, John Tierney, and John W. Gillespie Jr., “Formability of TuFF Composite Blanks”, SAMPE Conference Proceedings. Charlotte, NC, May 20-23, 2019. 9. Dirk Heider, John Tierney, Joseph Deitzel, Munetaka Kubota, John Thiravong, Verena Gargitter, Winona Burris, John Morris, Nicholas Shevchenko, Shridhar Yarlagadda, and John W. Gillespie, Jr., “Closed Loop Recycling of CFRP into Highly Aligned High Performance Short Fiber Composites Using The TuFF Process,” SAMPE Conference Proceedings. Charlotte, NC, May 20-23, 2019.

Conference: SAMPE 2019 - Charlotte, NC

Publication Date: 2019/05/20

SKU: TP19--1605

Pages: 12

Price: FREE