Title: Effects of Carbon Nanofiber Z-Threads on the Longitudinal Compressive Strength of Unidirectional CFRP Laminates
Authors: Sebastian Kirmse, Keonhyeong Kim, Bikash Ranabhat, and Kuang-Ting Hsiao
Abstract: In this study, unidirectional carbon fiber prepregs that contain long carbon nanofiber (CNF) z threads as a through-thickness (z-directional) reinforcement were manufactured. The CNF z threads are long enough to thread through multiple carbon fiber (CF) arrays, which creates a multi-scale CNF/CF/resin-composite. The CNF z-threaded prepregs were manufactured using an electric-field aligned flow-transferring process. It was hypothesized that the CNF z-threads with the zig-zag threading pattern reinforces the interlaminar and intralaminar regions of the CFRP laminate thus improve the compressive strength by reducing the chance of carbon fiber buckling. Compressive testing was performed per modified version of ASTM D695 (i.e., SACMA SRM 1R 94) to evaluate the compressive strength of the CNF z-threaded CFRP (ZT-CFRP) laminates. The samples were manufactured using AS4 carbon fibers, EPON 862/Epikure-W resin and 1wt% CNF content. ZT-CFRP testing results were compared with unaligned CNF-modified CFRP (UA-CFRP) and unmodified CFRP samples to investigate the impact of the CNF z-threads on the compressive strength. Results showed an increase of ~15% for the compressive strength of ZT CFRPs, whereas the UA-CFRPs experienced a decrease of ~8% when compared to unmodified CFRPs. It was concluded that CNF/carbon fiber interlocking stops and delays crack growth and helps to stabilize carbon fibers from further buckling.
References: 1. Spitalsky, Z., Tasis, D., Papagelis, K., and Galiotis, C. “Carbon nanotube – polymer composites: Chemistry, processing, mechanical and electrical properties,” Progress in Polymer Science 35(3) (2010): 357–401. DOI: 10.1016/j.progpolymsci.2009.09.003. 2. Hsiao, K.-T., and Hickman, G.J.S. “Novel Method for Manufacturing Nano-Structurally Aligned Multi-Scale Composites,” US 2016/0168342 A1, 2016. 3. Hsiao, K.T., Scruggs, A.M., Brewer, J.S., Hickman, G.J.S., McDonald, E.E., and Henderson, K. “Effect of carbon nanofiber z-threads on mode-I delamination toughness of carbon fiber reinforced plastic laminates,” Composites Part A: Applied Science and Manufacturing 91 (2016): 324–335. DOI: 10.1016/j.compositesa.2016.10.022. 4. Scruggs, A.M., Henderson, K., and Hsiao, K. “Characterization of Electrical Conductivity of a Carbon Fiber Reinforced Plastic Laminate Reinforced With Z-Aligned Carbon Nanofibers,” in Proceedings of CAMX 2016 (The Composites and Advanced Materials Expo), Anaheim, CA, Sept. 26-29, 2016, TP16-0137. 5. Scruggs, A.M. “Enhancement of Through-Thickness Electrical Conductivity Due to Carbon Nanofiber Z-Threads in Unidirectional Carbon Fiber Reinforced Plastic Laminates,” [M.S. Thesis]. Department of Mechanical Engineering, University of South Alabama, Mobile, Alabama, 2018. 6. Ranabhat, B., and Hsiao, K. “Improve the Through-Thickness Electrical Conductivity of Cfrp Improve the Through-Thickness Electrical Conductivity of CFRP Laminate Using Flow- Aligned Carbon Nanofiber Z-Threads,” in Proceedings of SAMPE 2018 (Society for the Advancement of Material and Process Engineering), Long Beach, CA, May, 21-24, 2018, SE18--1100. 7. Scruggs, A.M., Kirmse, S., and Hsiao, K.-T. “Enhancement of Through-Thickness Thermal Transport in Unidirectional Carbon Fiber Reinforced Plastic Laminates due to the Synergetic Role of Carbon Nanofiber Z-Threads,” Journal of Nanomaterials 2019 (2019): 1–13. DOI: 10.1155/2019/8928917. 8. Kirmse, S. “Interlaminar Shear Strength Enhancement of Unidirectional Carbon Fiber Reinforced Plastic Laminates Using a Carbon Nanofiber Z-Threading Technique,” [M.S. Thesis]. Department of Mechanical Engineering, University of South Alabama, Mobile, Alabama, 2018. 9. Kirmse, S., and Hsiao, K.-T. “Enhancing the Interlaminar Shear Strength of Unidirectional Carbon Fiber Reinforced Plastic (CFRP) Laminate Using a Nanofiber Z-Threading Strategy,” in Proceedings of CAMX 2018 (The Composites and Advanced Materials Expo), Dallas, TX, Oct. 15-18, 2018, TP18-0499. 10. Anand, A., Harshe, R., and Joshi, M. “Resin film infusion: Toward structural composites with nanofillers,” Journal of Applied Polymer Science 129(3) (2013): 1618–1624. DOI: 10.1002/app.38855. 11. Zhou, Y., Jeelani, S., and Lacy, T. “Experimental study on the mechanical behavior of carbon/epoxy composites with a carbon nanofiber-modified matrix,” Journal of Composite Materials 48(29) (2014): 3659–3672. DOI: 10.1177/0021998313512348. 12. Iwahori, Y., Ishiwata, S., Sumizawa, T., and Ishikawa, T. “Mechanical properties improvements in two-phase and three-phase composites using carbon nano-fiber dispersed resin,” Composites Part A: Applied Science and Manufacturing 36(10) (2005): 1430–1439. DOI: 10.1016/j.compositesa.2004.11.017. 13. Liu, F., Deng, S., and Zhang, J. “Mechanical Properties of Epoxy and Its Carbon Fiber Composites Modified by Nanoparticles,” Journal of Nanomaterials 2017 (2017): 1–9. DOI: 10.1155/2017/8146248. 14. Sharma, S.P., and Lakkad, S.C. “Compressive strength of carbon nanotubes grown on carbon fiber reinforced epoxy matrix multi-scale hybrid composites,” Surface and Coatings Technology 205(2) (2010): 350–355. DOI: 10.1016/j.surfcoat.2010.06.055. 15. “Pyrograf-III Carbon Nanofiber.” [Online]. Available: http://pyrografproducts.com/nanofiber.html#_PR-24-XT-HHT_Data_Sheet. [Accessed: 01-Oct-2018]. 16. Hsiao, K.-T., and Gangireddy, S. “Investigation on the spring-in phenomenon of carbon nanofiber-glass fiber/polyester composites manufactured with vacuum assisted resin transfer molding,” Composites Part A: Applied Science and Manufacturing 39(5) (2008): 834–842. DOI: 10.1016/j.compositesa.2008.01.015. 17. Sadeghian, R., Gangireddy, S., Minaie, B., and Hsiao, K.-T. “Manufacturing carbon nanofibers toughened polyester/glass fiber composites using vacuum assisted resin transfer molding for enhancing the mode-I delamination resistance,” Composites Part A: Applied Science and Manufacturing 37(10) (2006): 1787–1795. DOI: 10.1016/j.compositesa.2005.09.010. 18. Lake, P.D. “Pyrograf III,” Applied Sciences, Inc., 2012. [Online]. Available: http://apsci.com/?page_id=19. [Accessed: 01-Nov-2018]. 19. Ozkan, T., Chen, Q., Naraghi, M., and Chasiotis, I. “Mechanical and interface properties of carbon nanofibers (CNFs) for polymer nanocomposites,” in 53rd International SAMPE symposium proceedings (Society for the Advancement of Material and Process Engineering), Memphis, TN, Sep. 8–11, 2008, 2008. 20. Qin, Q.H. “Introduction to the composite and its toughening mechanisms,” in Toughening Mechanisms in Composite Materials, Q. Qin and J. Ye, Eds. Australian National University, Acton, ACT, Australia: Woodhead Publishing Series in Composites Science and Engineering, 2015, 1–32. DOI: 10.1016/B978-1-78242-279-2.00001-9. 21. “SACMA Recommended Test Method for Compressive Properties of Oriented Fiber-Resin Composites (SRM 1R-94),” Supplier of Advanced Composite Materials Association (SACMA). 22. Hsiao, H.M., and Daniel, I.M. “Effect of fiber waviness on stiffness and strength reduction of unidirectional composites under compressive loading,” Composites Science and Technology 56(5) (1996): 581–593. DOI: 10.1016/0266-3538(96)00045-0. 23. Cho, J., Chen, J.Y., and Daniel, I.M. “Mechanical enhancement of carbon fiber/epoxy composites by graphite nanoplatelet reinforcement,” Scripta Materialia 56(8) (2007): 685–688. DOI: 10.1016/j.scriptamat.2006.12.038. 24. Wei, W., Rongjin, H., Chuanjun, H., Zhao, Y., Li, S., and Laifeng, L. “Cryogenic performances of T700 and T800 carbon fibre-epoxy laminates,” IOP Conference Series: Materials Science and Engineering 102(012016) (2015): . DOI: 10.1088/1757-899X/102/1/012016.
Conference: SAMPE 2019 - Charlotte, NC
Publication Date: 2019/05/20
Price: FREEGet This Paper