Title: Fastening Aerospace Structures with Carbon Fiber/Polyether Ether Ketone Composite Rivets

Authors: Christophe Absi, Nawaf Alsinani, Louis Laberge Lebel

DOI: 10.33599/nasampe/s.21.0584

Abstract: High specific properties make composite materials desirable for modern aerospace applications. However, joining such materials presents new challenges. Notably, composites are not capable of supporting the high localized loads caused by deforming aluminum solid rivets, traditionally used for joining aluminum structures. Instead, metallic bolt-type fasteners are used. However, such fasteners present drawbacks regarding their weight, lightning strike hazards, corrosion, and cost. We present here the development of an innovative assembly technology to overcome these downfalls, with carbon fiber/thermoplastic composite rivets. First, carbon fiber/polyether ether ketone (CF/PEEK) rods are pultruded and cut into short length blanks. Then, by Joule effect, the blank is heated above the melting temperature of the thermoplastic matrix. Next, it is molded in situ, i.e., into steel or carbon fiber reinforced polymer (CFRP) adherends. To ensure consistency, the riveting process is performed by an automated machine. In steel, up to 175 W of heating were applied, while only 110 W were used for CFRP plates. The riveting process required 35 s. Shear and tension test results showed higher specific properties than similar joints featuring aerospace-grade titanium fasteners. CF/PEEK rivets submitted to shear held 9 kN/g, while titanium fasteners held 5 kN/g. For samples submitted to tension, CF/PEEK rivets held 5.6 kN/g, while titanium fasteners held between 3 kN/g and 5.5 kN/g. These superior specific mechanical properties show that the technology could be used in the next generation of lighter and safer aircraft structures.

References: 1. Slayton, R. and G. Spinardi Radical innovation in scaling up: Boeing’s Dreamliner and the challenge of socio-technical transitions. Technovation, 2016. 47, 47-58 DOI: 10.1016/j.technovation.2015.08.004. 2. Poullos, M., Manufacturing Technology for Low-Cost Composite Fasteners, Final Report, Phases I and II. 1979, Flight Dynamics Laboratory, Air Force Wright Aeronautical Laboratories, Air Force Systems Command, Wright-Patterson Air Force Base: Ohio. 3. Cole, B. and E.J. Bateh, Special fastener development for composite structure. 1982, Flight Dynamics Laboratory, Air Force Wright Aeronautical Laboratories, Air Force Systems Command, Wright-Patterson Air Force Base: Ohio. p. 181. 4. Mulazimoglu, H. and L. Haylock. Recent Developments in Techniques to Minimize Lightning Current Arcing Between Fasteners and Composite Structure. in International Conference on Lightning & Static Electricity (ICOLSE). 2011. Oxford, UK. 5. Fortier, V., J.-E. Brunel, and L. Laberge Lebel, Automated Manufacturing of Thermoplastic Composite Rivets, in 10th Canadian-International Conference on Composites. 2017: Ottawa, Canada. 6. Fortier, V., F. Lessard, and L. Laberge Lebel. Fastening Composite Structures Using Carbon Fiber/Polyetherimide Rivets. in 12th Canada-Japan Workshop on Composites. 2018. Gifu Takayama, Japan. 7. Ueda, M., N. Ui, and A. Ohtani, Lightweight and anti-corrosive fiber reinforced thermoplastic rivet. Composite Structures, 2018. 188: p. 356-362. 8. Ohtani, A., Fracture behavior and mechanical properties of rivet joint by using ultrasonic vibration with C-FRTP, in 12th Canada-Japan Workshop on Composites. 2018: Takayama, Gifu, Japon. 9. T. Eguchi, T. Mimura, and T. Hida, Development of rivet fastening process by servo press machine using unidirectional CFRTP rod, in 4th International Conference & Exhibition on Thermoplastic Composites (ITHEC 2018). 2018: Bremen, Germany. 10. Fortier, V., J.-E. Brunel, and L. Laberge Lebel Fastening composite structures using braided thermoplastic composite rivets. Journal of Composite Materials, 2019. DOI: 10.1177/0021998319867375. 11. Absi, C., et al., Carbon Fiber/Polyether Ether Ketone Rivets for Fastening Composite Structures, in 22nd International Conference on Composite Materials (ICCM22). 2019: Melbourne, Australia. 12. Lanciotti, A. and C. Polese The effect of interference-fit fasteners on the fatigue life of central hole specimens. Fatigue & Fracture of Engineering Materials & Structures, 2005. 28, 587-597 DOI: 10.1111/j.1460-2695.2005.00902.x. 13. Cole, R.T., E.J. Bateh, and J. Potter Fasteners for composite structures. Composites, 1982. 13, 233-240 DOI: 10.1016/0010-4361(82)90005-2. 14. McCarthy, M.A., et al., Bolt-hole clearance effects and strength criteria in single-bolt, single-lap, composite bolted joints. Composites Science and Technology, 2002. 62(10-11): p. 1415-1431. 15. McCarthy, C.T. and M.A. McCarthy, Design and failure analysis of composite bolted joints for aerospace composites, in Polymer Composites in the Aerospace Industry, P.E. Irving and C. Soutis, Editors. 2015, Woodhead Publishing. p. 295-334. 16. Green, L.B., Fastening member, United States Patent 2510693, Application Number US52859344A 1950. 17. Hutchins, J.G. Update of Composite Fastener Technology at BHTI. SAE Technical Paper Series, 1991. DOI: 10.4271/912648. 18. Mizushima, G., Propriétés mécaniques des boulons en composites. Composites, Plastiques renforcés, fibres de verre textile, 1993. 6: p. 32-35. 19. Schuett, M., et al. Experimental and analytical study of an CF-PEEK Fastener all composites single-lap shear joint under static and fatigue loading. CEAS Aeronautical Journal, 2019. 10, 565-587 DOI: 10.1007/s13272-018-0334-z. 20. Laberge Lebel, L. and V. Fortier, Apparatus and methods for installing composite rivets, Patent PCT/IB2018/051448. 2017. 21. Absi, C., N. Alsinani, and L. Laberge Lebel, Carbon fiber reinforced poly(ether ether ketone) rivets for fastening composite structures. Manuscript submitted for publication, 2021. 22. Trudeau, P., et al., Composite rivet blank installation thereof, International Patent WO 2015/132766 A1, Application Number 15/123,084. 2017

Conference: SAMPE NEXUS 2021

Publication Date: 2021/06/29

SKU: TP21-0000000584

Pages: 16

Price: FREE