DOI QR코드

DOI QR Code

Aging Characteristics of Carbon Fiber/Epoxy Composite Ring Specimen

탄소섬유/에폭시 복합재 링 시편의 노화 특성 평가

  • 윤성호 (금오공과대학교 기계공학부) ;
  • 오진오 (금오공과대학교 기계공학과)
  • Published : 2009.12.31

Abstract

The effect of exposure times on the aging characteristics of carbon fiber/epoxy composite ring specimen was evaluated using an accelerating aging tester. Combined exposure conditions, such as temperature, moisture, and ultraviolet, were applied up to 3000 hours. Tensile properties and flexural properties including the effect of curvature were evaluated on the specimens subject to various exposure times through a material testing system. Their aging surfaces were observed through a scanning electron microscope. According to the results, tensile modulus was little affected by the exposure times. However, tensile strength, at the early stage of the exposure times, increased due to physical aging and curing reaction, but tensile strength slightly decreased due to degradation as the exposure times increased. The flexural modulus and flexural strength increased at the early stage of the exposure times, but slightly decreased as the exposure times increased. Aging surfaces of the specimens examined using the scanning electron microscope revealed a different morphology in various exposure times and provided useful information for identifying the degradation in mechanical properties of the composite subject to various exposure times.

가속노화장치를 이용하여 노출시간에 따른 탄소섬유/에폭시 복합재 링 시편의 노화 특성을 평가하였다. 온도, 수분, 자외선 등의 복합적인 노출조건은 최대 3000시간까지 적용하였다. 노출시간에 따른 링 시편의 인장특성과 곡률의 영향이 고려된 굽힘특성은 하중시험장치를 이용하여 평가하였으며 노화표면은 전자현미경을 통해 관찰하였다. 연구결과에 따르면 인장강성은 환경인자의 노출시간에 큰 영향을 받지 않지만 인장강도는 노출 초기에 물리시효 현상과 경화 반응으로 다소 증가하지만 노출시간이 길어지면 열화 영향으로 감소하였다. 굽힘탄성계수와 굽힘강도는 노출초기에 다소 증가하지만 노출시간이 길어지면 감소하는 양상을 나타내었다. 또한 전자현미경을 통해 관찰된 노화표면은 환경인자의 노출시간에 따라 달라지기 때문에 환경인자의 노출시간에 따른 기계적 특성의 변화를 규명하기 위한 정보를 제공해 준다.

Keywords

References

  1. Dao B., Hodgkin J., Krstina J., Mardel J., and Tian W., "Accelerated Aging Versus Realistic Aging in Aerospace Composite Materials. Ⅰ. The Chemistry of Thermal Aging in a Low-Temperature-Cure Epoxy Composite," Journal of Applied Polymer Science, Vol. 102, No. 5, 2006, pp. 4291-4303 https://doi.org/10.1002/app.24862
  2. Selden R., Nystrom B., and Langstrom R., "UV Aging of Poly(propylene)/Wood-fiber Composites," Polymer Composites, Vol. 25, No. 5, 2004, pp. 543-553 https://doi.org/10.1002/pc.20048
  3. Kim D. J., Choi N. S., and Yoon Y. J., "Degradation Characteristics of Filament-Winding-Laminated Composites Under Accelerated Environmental Test," Transactions of The Korean Society of Mechanical Engineers, Part A, Vol. 31, No. 3, 2007, pp. 295-303 https://doi.org/10.3795/KSME-A.2007.31.3.295
  4. Yoon, S. H., Lee, S. J., and Lee, J. K., "Effects of Combined Environmental Factors on Mechanical and Thermal Analysis Properties of Graphite/Epoxy Composites," Transactions of The Korean Society of Mechanical Engineers, Vol. 13, No. 5, 2002, pp. 1416-1425 https://doi.org/10.3795/KSME-A.2002.26.7.1416
  5. Yoon S. H., Nam J. P., Hwang Y. E., Lee S. J., and Shin K. B., "Aging Characteristics of Glass Fabric/Phenolic Composites for Tilting Train Using Accelerated Aging Tester," Journal of The Korean Society of Railway, Vol.8, No. 2, 2005, pp. 188-194
  6. ASTM G155, "Standard Practice for Operating Xenon Arc Light Apparatus for Exposure of Non-metallic Materials," Annual Book of ASTM Standards, Vol .14.04, 2001
  7. ASTM D2290, "Standard Test Method for Apparent Hoop Tensile Strength of Plastic or Reinforced Plastic Pipe by Split Disk Method," Annual Book of ASTM Standards, Vol. 08.01, 2002
  8. Yoon S. H., Kim C. G., Cho W. M., "Measurement of Tensile Properties Using Filament Wound Ring Specimens," Journal of Reinforced Plastics and Composites, Vol. 16, No. 9, 1997, pp. 810-824 https://doi.org/10.1177/073168449701600903
  9. Yoon S. H., Kim C. G., Cho W. M., "Comparison of Tensile Properties Between Ring Specimen and Tensile Coupon Specimen Manufactured By Filament Winding Process," Journal of The Korean Society for Composite Materials, Vol. 8, No. 2, 1995, pp. 52-60
  10. ASTM D790, "Standard Test Method for Flexural Properties of Unreinforced and Reinforced Plastics and Electrical Insulating Materials," Annual Book of ASTM Standards, Vol.08.01, 2002