Durability of Carbon/Epoxy Composites for Train Carbody under Salt Water Environment

염수환경에 노출된 철도차량용 탄소섬유/에폭시 복합재의 내구성 평가

  • 윤성호 (금오공과대학교, 기계공학부) ;
  • 황영은 (금오공과대학교, 기계공학부) ;
  • 김정석 (한국철도기술연구원, 철도구조연구실) ;
  • 윤혁진 (한국철도기술연구원, 철도구조연구실) ;
  • Published : 2008.08.30

Abstract

This study investigates the durability of carbon/epoxy composites for use on train car bodies under a salt water spray environment. Salt water solution with 5% NaCl, similar to natural salt water, was used for the salt water environmental tests. The specimens were obtained from a composite panel consisting of an epoxy matrix reinforced with T700 carbon fabric. The specimens were exposed to the salt water environment for up to 12 months. Mechanical tests were performed to obtain tensile properties, flexural properties, and shear properties. Dynamic mechanical analysis was used to measure such thermal properties as storage modulus, loss modulus, and tan $\delta$. Also FT/IR tests were conducted to investigate changes in chemical structure with exposure. The results revealed that fiber-dominated mechanical properties were not affected much by exposure time, but matrix-dominated mechanical properties decreased with increasing exposure time. Storage modulus was not very sensitive to exposure time, but glass transition temperature was affected, slightly decreasing with increasing exposure time. Although the peak intensity of FT/IR curves was affected slightly by exposure time, the peak shape and peak location of FT/IR curves were not noticeably changed. Carbon/epoxy composites used for this study were relatively stable to the salt water environment.

References

  1. Jamond, R. M., Caceres, A., Hoffard, T. A. and Malvar, L. J. (2000), "Accelerated Testing of Fiber Reinforced Polymer Matrix Composites - Test Plan," NFESC Special Publication SP-2091- SHR.
  2. Hammami, A. and Al-Ghuilani, N. (2004), "Durability and Environmental Degradation of Glass-Vinylester Composites," Polymer composites, Vol. 25, No. 6, December, pp. 609-616. https://doi.org/10.1002/pc.20055
  3. ASTM B117-97 (1997), Annual Book of ASTM Standards, 03.02, American Society for Testing and Materials.
  4. ASTM D3039/D3039M-00 (2001), Annual Book of ASTM Standards, 15.03, American Society for Testing and Materials
  5. Caceres, A., Jamond, R. M., Hoffard, T. A. and Malvar, L. J. (2002), "Salt-Fog Accelerated Testing of Glass Fiber Reinforced Polymer Composites," NFESC Technical Report TR-2215-SHR.
  6. Kootsookos, A. and Mouritz, A. P. (2004), "Seawater Durability of Glass- and Carbon-Polymer Composites," Composites Science and Technology, 64, pp.1503-1511. https://doi.org/10.1016/j.compscitech.2003.10.019
  7. Donald, L. P., Gary, M. L. and George, S. K. (1998), Introduction to Spectroscopy, Saunders College Publishing.
  8. Zhang, S., Karbhari, V. M., Mai, L. Y. and Mai, Y. W. (2000), "Evaluation of Property Retention in E-Glass/Vinylester Composites after Exposure to Salt Solution and Natural Weathering," Journal of Reinforced Plastics and Composites, Vol. 19, No. 9, pp. 704-731. https://doi.org/10.1106/9CB7-UN5W-FWCN-8DE1
  9. ASTM D5379/D5379M-98 (2001), Annual Book of ASTM Standards, 15.03, American Society for Testing and Materials.
  10. Fried, J. R. (2003), Polymer Science and Technology, Prentice- Hall of India.
  11. Wolff, E. G. (1993), "Moisture Effects on Polymer Matrix Composites," SAMPE Journal, Vol. 29, No. 3, pp.11-19.
  12. Yoon, S. H. (2005), "Evaluation of Durability for Glass Fabric/Phenolic Composites under Salt Water Environment," Journal of Composite Materials, Vol. 18, No. 4, August, pp. 27-33.
  13. Jamond, R. M., Hoffard, T. A., Novinson, T. and Malvar, L. J. (2000), "Composites in Simulated Marine Environments," NFESC Special Publication SP-2083-SHR.
  14. ASTM D790-00 (2001), Annual Book of ASTM Standards, 08.01, American Society for Testing and Materials.
  15. Catherine, A. W. and Walter, L. B. (1997), "Determination of the Effect of Seawater on the Interfacial Strength of an Interlayer EGlass/ Graphite/Epoxy Composite by in SITU Observation of Transverse Cracking in an Environmental SEM," Composites Science and Technology 57, pp.1033-1043. https://doi.org/10.1016/S0266-3538(96)00170-4