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Analysis of Apparent Fracture Toughness of a Thick-Walled Cylinder with an FGM Coating at the Inner Surface Containing a Radial Edge Crack

반경방향의 모서리 균열을 갖고 내면이 경사기능재료(FGM)로 코팅된 두꺼운 실린더의 겉보기 파괴인성해석

  • Afsar, A.M. (Dept. of Mechanical Engineering, Changwon National University) ;
  • Rasel, S.M. (Dept. of Mechanical Engineering, Changwon National University) ;
  • Song, J.I. (Dept. of Mechanical Engineering, Changwon National University,)
  • Published : 2010.04.30

Abstract

This study analyzes the apparent fracture toughness of a thick-walled cylinder with a functionally graded material (FGM) coating at the inner surface of the cylinder. The cylinder is assumed to have a single radial edge crack emanating from its inner surface. The crack surfaces and the inner surface of the cylinder are subjected to an internal pressure. The incompatible eigenstrain developed in the cylinder due to nonuniform coefficient of thermal expansion as a result of cooling from sintering temperature is taken into account. Based on a method of evaluating stress intensity factor introduced in our previous study, an approach is developed to calculate apparent fracture toughness. The approach is demonstrated for a cylinder with a TiC/$Al_{2}O_{3}$ FGM coating and some numerical results of apparent fracture toughness are presented graphically. The effects of material distribution profile, cylinder wall thickness, application temperature, and coating thickness on the apparent fracture toughness are investigated in details. It is found that all of these factors play an important role in controlling the apparent fracture toughness of the cylinder.

본 연구는 실린더 내부가 경사가능재료로 코팅된 두꺼운 벽을 가진 실린더의 겉보기 파괴인성치를 해석한 것이다. 실린더는 내부로부터 반경방향의 단일 모서리 균열이 내재되어 있으며, 균열면과 내면에는 내압을 받고 있는 것으로 가정하였다. 소결온도로부터 냉각 결과 균일한 열팽창계수로 인해 실린더에는 비적합 고유스트레인이 생성되었다. 기존의 연구에서 소개된 응력확대계수 평가법에 기초해 겉보기 파괴인성치를 계산하였다. 본 연구에서는 TiC/$Al_{2}O_{3}$ FGM 코팅된 실린더를 사용하였고 겉보기 파괴인성치의 수치적인 결과를 도식화하였다. 재료분포프로파일, 실린더 벽 두께, 적용온도와 코팅두께등이 겉보기 파괴인치에 미치는 영향이 상세히 조사되었으며, 이러한 모든 인자는 실린더의 겉보기 파괴인성치를 조절하는데 중요한 역할을 하는 것으로 밝혀졌다.

Keywords

References

  1. Yamanouchi, M., Koizumi, M., Hirai T., and Shiota I., "Proceedings of the First International Symposium on Functionally Gradient Materials," Sendai, Japan, 1990.
  2. Holt, J.B., Koizumi M., Hirai T., and Munir Z.A., Ceramic Transactions: Functionally Gradient Materials, Vol. 34, The American Ceramic Society, Westerville, OH, 1993.
  3. Ilschner B. and Cherradi N., "Proceedings of the Third International Symposium on Structural and Functional Gradient Materials," Presses Polytechniques et Universitaires Romands, Lausanne, Switzerland, 1994.
  4. Chen Y.F. and Erdogan F., "The Interface Crack Problem for a Nonhomogeneous Coatings Bonded to a Homogeneous Substrate," Journal of the Mechanics and Physics of Solids, Vol. 44, 1996, pp. 771-787. https://doi.org/10.1016/0022-5096(96)00002-6
  5. Gu P. and Asaro R.J., "Cracks in Functionally Graded Materials," International Journal of Solids and Structures, Vol. 34, 1997, pp. 1-17. https://doi.org/10.1016/0020-7683(95)00289-8
  6. Ozturk M. and Erdogan F., "An Axisymmetric Crack in Bonded Materials with a Nonhomogeneous Interfacial Zone under Torsion," ASME Journal of Applied Mechanics, Vol. 62, 1995, pp. 116-125. https://doi.org/10.1115/1.2895891
  7. Ozturk M. and Erdogan F., "Axisymmetric Crack Problem in Bonded Materials with a Graded Interfacial Region," International Journal of Solidsand Structures, Vol. 33, 1996, pp. 193-219. https://doi.org/10.1016/0020-7683(95)00034-8
  8. Choi H.J., "Bonded Dissimilar Strips with a Crack Perpendicular to the Functionally Graded Interface," International Journal of Solids and Structures, Vol. 33, 1996, pp. 4101-4117. https://doi.org/10.1016/0020-7683(95)00270-7
  9. Bao G. and Wang L., "Multiple Cracking in Functionally Graded Ceramic/Metal Coatings," International Journal of Solids and Structures, Vol. 32, 1995, pp. 2853-2871. https://doi.org/10.1016/0020-7683(94)00267-Z
  10. Hassan H.A.Z., "Torsion of a Nonhomogeneous Infinite Elastic Cylinder Slackened by a Circular Cut," Journal of Engineering Mathematics, Vol. 30, 1996, pp. 547-555. https://doi.org/10.1007/BF00036617
  11. Zuiker J.R., "Functionally Graded Materials: Choice of Micromechanics Model and Limitations in Property Variation," Composites Engineering, Vol. 5, 1995, pp. 807-819. https://doi.org/10.1016/0961-9526(95)00031-H
  12. Sekine H. and Afsar A.M., "Composition Profile for Improving the Brittle Fracture Characteristics in Semi-Infinite Functionally Graded Materials," JSME International Journal, Series A, Vol. 42, 1999, pp. 592-600. https://doi.org/10.1299/jsmea.42.592
  13. Afsar A.M. and Sekine H., "Crack Spacing Effect on the Brittle Fracture Characteristics of Semi-Infinite Functionally Graded Materials with Periodic Edge Cracks," International Journal of Fracture, Vol. 102, 2000, pp. L61-L66. https://doi.org/10.1023/A:1007640524635
  14. Mura T., Micromechanics of Defects in Solids: Mechanics of Elastic and Inelastic Solids, Kluwer Academic Publishers, Dordrecht, The Netherlands, 1987.
  15. Afsar A.M., and Sekine H., "Optimum Material Distributions for Prescribed Apparent Fracture Toughness in Thick-Walled FGM Circular Pipes," International Journal of Pressure Vessels and Piping, Vol. 78, 2001, pp. 471-484. https://doi.org/10.1016/S0308-0161(01)00061-8
  16. Afsar A.M. and Sekine H., "Inverse Problems of Material Distributions for Prescribed Apparent Fracture Toughness in FGM Coatings Around a Circular Hole in Infinite Elastic Media," Composites Science and Technology, Vol. 62, 2002, pp. 1063-1077. https://doi.org/10.1016/S0266-3538(02)00049-0
  17. Afsar A.M. and Anisuzzaman M., "Stress Intensity Factors of Two Diametrically Opposed Edge Cracks in a Thick-Walled Functionally Graded Material Cylinder," Engineering Fracture Mechanics, Vol. 74, 2007, pp. 1617-1636. https://doi.org/10.1016/j.engfracmech.2006.09.001
  18. Afsar A.M., Anisuzzaman M., and Song, J.I., "Inverse Problem of Material Distribution for Desired Fracture Characteristics in a Thick-Walled Functionally Graded Material Cylinder with Two Diametrically-Opposed Edge Cracks," Engineering Fracture Mechanics, Vol. 76, 2009, pp. 845-855. https://doi.org/10.1016/j.engfracmech.2008.12.003
  19. Afsar A.M. and Song J.I., "Analysis of Apparent Fracture Toughness of a Thick-Walled FGM Cylinder with Two DiametricalIy Opposed Edge Cracks," Fracture and Fatigue of Engineering Materials and structures, in press.
  20. Nan C.W., Yuan R.Z., and Zhang L.M ., The Physics of Metal/Ceramic Functionally Gradient Materials. Ceramic Transaction: Functionally Gradient Materials,Holt J.B. et al (ed), Vol. 34, American Ceramic Society, Westerville, Oh, 1993, pp. 75-82.
  21. Bowie O.L. and Freese C.E., "Elastic Analysis for a Radial Crack in a Circular Ring," Engineering Fracture Mechanics, Vol. 4, 1972, pp. 315-321. https://doi.org/10.1016/0013-7944(72)90045-8
  22. Nair S.V., "Crack-Wake Debonding and Toughness in Fiber-or Whisker-Reinforced Brittle-Matrix Composites," Journal of American Ceramic Society, Vol. 73, 1990, pp. 2839-2847. https://doi.org/10.1111/j.1151-2916.1990.tb06684.x

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