Nondestructive Interfacial Evaluation and fiber fracture Source Location of Single-Fiber/Epoxy Composite using Micromechanical Technique and Acoustic Emission

음향방출과 미세역학적시험법을 이용한 단일섬유강화 에폭시 복합재료의 비파지적 섬유파단 위치표정 및 계면물성 평가

  • 박종만 (경상대학교 응용화학공학부, 항공기부품기술연구센터) ;
  • 공진우 (한국기계연구원 복합재료그룹) ;
  • 김대식 (경상대학교 응용화학공학부, 항공기부품기술연구센터) ;
  • 윤동진 (한국표준과학연구원 스마트계측그룹)
  • Published : 2003.10.30

Abstract

Fiber fracture is one of the dominant failure phenomena affecting the total mechanical Performance of the composites. Fiber fracture locations were measured through the conventional optical microscope and the nondestructive acoustic emission (AE) technique and then were compared together as a function of the epoxy matrix modulus and the fiber surface treatment by the electrodeposition method (ED). Interfacial shear strength (IFSS) was measured using tensile fragmentation test in combination of AE method. ED treatment of the fiber surface enlarged the number of fiber fracture locations in comparison to the untreated case. The number of fiber fracture events measured by the AE method was less than optically obtained one. However, fiber fracture locations determined by AE detection corresponded with those by optical observation with small errors. The source location of fiber breaks by AE analysis could be a nondestructive, valuable method to measure interfacial shear strength (IFSS) of matrix in non-, semi- and/or transparent polymer composites.

섬유파단은 복합재료의 기계적물성을 규명하는 가장 중요한 현상 중 하나이며, 섬유파단 위치는 기지재료의 물성과 섬유표면 처리에 따라 광학현미경에 의한 방법뿐만 아니라 음향방출법을 이용하여 확인 및 상호비교 할 수 있다. 두 개의 음향방출 센서를 단일섬유강화 에폭시 복합재료 시편 표면에 부착 시켜 연속적인 섬유파단 신호를 변형률과 측정 시간에 따라 감지하였으며, 계면전단강도는 단일섬유강화 복합재료 시험에서 광학적 방법과 음향방출법을 이용하여 측정하였다. 탄소섬유의 파단 수는 섬유표면을 전기증착으로 처리한 경우가 많았으며, 광학적인 관찰 시에 좀 더 많게 나타났다. 하지만 음향방출법과 광학적 방법에 의한 섬유파단의 위치는 작은 오차범위 내에서 상호 잘 일치하는 결과를 얻을 수 있었다. 음향방출법에 의한 섬유파단 위치표정과 파형분석은 투명, 반투명 및 불투명한 복합재료의 계면물성을 비파괴적으로 측정하기 위한 유용한 방법으로 사료된다.

Keywords

References

  1. Q. Q. Ni and E. Jinen, 'Fracture behavior and acoustic emission in bending test on single-fiber composites', Eng. Fracture Mech., Vol. 56, No.6, pp. 779-796, (1997) https://doi.org/10.1016/S0013-7944(97)00001-5
  2. J. M. Park, Y. M. Kim and J. W. Kim, 'Interfacial aspects of electrodeposited carbon fiber-reinforced epoxy composites using monomeric and polymeric coupling agents', J. Colloid Interface Sci., Vol. 231, No.1, pp. 114-128, (2000) https://doi.org/10.1006/jcis.2000.7113
  3. T. Grubb and Z. F. u. 'Single-fiber polymer composites: Part I interfacial shear strength and stress distribution in the pullout test', J. Mater. Sci., Vol. 29, No.1, pp. 189-202, (1994) https://doi.org/10.1007/BF00356593
  4. M Kharrat, A Chateauminois, L. Carpentier and P. Kapsa, 'On the interfacial behaviour of a glass/epoxy composite during a microindentation test: assessment of interfacial shear strength using reduced indentation curves', Compos. Part A, Vol 28, No.1, pp. 39-46, (1997) https://doi.org/10.1016/S1359-835X(96)00092-9
  5. D. Rouby, 'Acoustic emission: a micro-investigation technique for interface mechanisms in fiber composites', J. Acoustic Emission, Vol 9, No.2, pp. 117-121, (1990)
  6. G. J. Farrow, J. D. H. Hughes and M. Darby, 'Acoustic emission from single carbon fibers and model microcomposites', J. Phys. D: Appl Phys., Vol 27, No.3, pp. 644-651, (1994)
  7. X. Lu, W. Sachse and I. Grabec, 'Use of an automatic modeler and a small receiver array for acoustic emission (AE) source location', Ultrasonics, Vol 36, No.5, pp. 539-547, (1998)
  8. S. I. Lee, J. M. Park, D. W. Shin and D. J. Yoon, 'Interfacial properties of glass fiber/brittle-ductile dual-matrix composites using micromechanical technique and acoustic emission', Polym. Compos., Vol 20, No.1, pp. 19-28, (1999)
  9. D. B. Marshall and W. C. Oliver, 'An introduction method for measuring residual stress in fiber reinforced ceramics', Mater. Sci. Eng., Vol. A126, No.1, pp. 95-103, (1990)
  10. J. M. Park, W. G. Shin and D. J. Yoon, 'Interfacial aspects of two basalt and SiC fiber reinforced epoxy composites using fragmentation technique and acoustic emission', Compos. Sci. Technol., Vol. 59, No.3, pp. 355-370, (1999) https://doi.org/10.1016/S0266-3538(98)00085-2
  11. A Manor and R. B. Clough, 'In-situ determination of fiber strength and segment length in composites by means of acoustic emission', Compos. Sci. Technol., Vol. 45, No.1, pp. 73-81, (1992) https://doi.org/10.1016/0266-3538(92)90124-L
  12. J. Eisenblatter, 'Acoustic emission analysis: Introduction, present status and future development, DGM Informations gesell schaft-Vlerlag, Oberursel., (1998)
  13. S. M. Ziola and M. R. Gorman, 'Source location in thin plates using cross-correlation', J. Acoustic Soc. Amer., Vol 90, pp. 2551-2556, (1991)
  14. M. Surgeon and M. Wevers, 'One sensor linear location of acoustic emission events using plate wave theories', Mater. Sci. Eng., Vol. A265, No.2, pp. 254-261, (1999) https://doi.org/10.1016/S0921-5093(98)01142-3
  15. A. N. Netravali, Z. F. Li and W. Sache, 'Determination of fiber/matrix interfacial shear strength by and acoustic emission techniques', J. Mater. set, Vol. 26, pp. 6631-6638, (1991)
  16. A R. Baker, 'The single fiber composite acoustic emission measurement system', MS Thesis, Cornell University, U. S. A, (1991)
  17. H. Jeong and Y. S. Jang, 'Wavelet analysis of plate wave propagation in composite laminates', Compos. Structures, Vol. 49, No. 4, pp. 443-450, (2000) https://doi.org/10.1016/S0263-8223(00)00079-9
  18. A. Kelly and W. R. Tyson, 'Tensile properties of fiber reinforced metals: copper/ tungsten and copper/molybdenum', Mech. Phys. Solids, Vol. 13, pp. 329-350, (1965)
  19. L. T. Drzal, 'The effect of polymeric matrix mechanical properties on the fiber-matrix interfacial shear strength', Mater. Sci. Eng., Vol 21, pp. 289-293, (1990)
  20. N. S. Choi, and K. Takahashi, 'Characterization of the damage process in short-fiber/thermoplastic composites by acoustic emission', J. Mater. sci, Vol. 33, No.9, pp. 2357-2363, (1998) https://doi.org/10.1023/A:1004347623040
  21. 'Standard test method for tensile strength and Young's modulus for high-modulus single-filament materials', ASTM D 3379-75, Reapproved, (1989)
  22. J. M. Park, S. I. Lee, J. w. Kim and D. J. Yoon, 'Interfacial properties of electrodeposited carbon fibers/epoxy composites using electro-micromechanical techniques and nondestructive evaluation', J. Colloid Interface sci, Vol 237, No. 1, pp. 80-90, (2001)