DOI QR코드

DOI QR Code

충격손상 복합재료의 피로수명에 대한 통계적 해석 연구

Probabilistic Approach for Fatigue Life of Composite Materials with Impact-Induced Damage

  • 강기원 (국립군산대학교 기계자동차공학부)
  • Kang, Ki-Weon (School of Mechanical and Automobile Engineering, Kunsan National University)
  • 투고 : 2010.08.18
  • 심사 : 2010.09.08
  • 발행 : 2010.09.30

초록

본 논문에서는 충격손상 복합재료의 피로수명 저하 특성과 이의 변동성을 통계적으로 분석하였다. 충격손상 복합재료의 잔류강도는 2모수 Weibull 분포에 잘 적합되었으며 충격에너지의 증가에 따라 잔류강도의 변동성은 감소 하였다. 복합재료의 피로수명은 충격손상에 의하여 크게 저하되었으며 또한 이의 피로수명에 대한 충격손상의 영향은 작용 응력진폭에 따라 변화함을 알 수 있었다. 또한 2모수 Weibull 분포를 이용하여 충격손상 복합재료의 피로수명의 변동성을 추정하였으며 충격에너지의 증강 및 응력진폭의 감소에 따라 피로수명의 변동성은 점차 감소하였다.

This paper presents the probabilistic analysis for fatigue life of Glass/Epoxy laminates with impact-induced damage. For this, a series of impact tests were perfomed on the Glass/Epoxy laminates using instrumented impact testing machine. Then, tensile and fatigue tests carried out so as to generate post-impact residual strength and fatigue life. Two Parameter Weibull distribution was used to fit the residual strength and fatigue life data of Glass/Epoxy composite laminates. The residual strength was affected by impact energy and their variance decreased with increasing of impact energy. The fatigue life of impacted laminates was greatly reduced by impact energy and this trend depended on applied stress amplitude. Additionally, the variation of fatigue life was gradually decreased with the applied stress amplitude.

키워드

참고문헌

  1. Abrate, S., "Impact on Laminated Composite Materials", Applied Mechanics Rev. Vol. 44, No 4, pp. 155-190, 1991 https://doi.org/10.1115/1.3119500
  2. Middleton, D.H., "Composite Materials in Aircraft Structures", pp. 207-227, 1990
  3. Park, J.H., Ha S.K., Kang, K.W., Kim, C.W. and Kim, H.S., "Impact Damage Resistance of Sandwich Structure subjected to Low Velocity Impact", Journal of Materials Processing Technology, Vol. 101, pp. 425-430, 2008
  4. 김도식, "유리섬유강화복합재료의 노치강도 및 피로 수명 예측에 관한 연구", 박사학위논문, 한양대학교, 1994
  5. Broutman, L. J. and Sahu, S., "A New Theory to Predict Cumulative Fatigue Damage in Fiberglass Reinforced Plastics", ASTM STP 497, pp. 170-188, 1972
  6. Yang, J. N., "Residual Strength Degradation Model and Theory of Periodic Proof Tests for Graphite/Epoxy Laminates", Journal of Composite Materials, Vol. 11, pp. 176-203, 1977 https://doi.org/10.1177/002199837701100205
  7. Kang, K.W. and Kim, J.K., "Fatigue Life Prediction of Impacted Carbon/Epoxy Laminates under constant amplitude Loading", Composites Part A, Vol. 35, pp. 529-535, 2004 https://doi.org/10.1016/j.compositesa.2004.01.024
  8. ASTM D 3039-00, "Standard Test Method for Tensile Properties of Fiber Resin Composite", 2000
  9. Kang K.W., S.K. Koh, D.K. Kim and K.J. Kim, "Assessment of the Statistical Distribution of Flexural Strength of Woven-Fabric Laminates with Impact- Induced Damage", Composite Structures, Vol. 90, pp. 60-66, 2009 https://doi.org/10.1016/j.compstruct.2009.02.001
  10. Weibull++7 User's manual, Reliasoft Inc, 2008