Advanced Composite Materials

The Korean Society for Composite Materials (한국복합재료학회)
권호 표지

Dependence of Weibull parameters on the diameter and the internal defects of Tyranno ZMI fiber in the strength analysis

  • Published : 2007.09.01
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Abstract

The single-modal Weibull model has been assessed on Tyranno ZMI Si-Zr-C-O fiber if a set of shape and scale parameters accurately reproduced the effect of the size of the diameter on strength. The tensile data of a single fiber have been divided into two expedient groups as 'small diameter' group and 'large diameter' group in deriving the parameters, which should be consistent if the Weibull model accurately reproduced the size effect. However, the derived Weibull parameters were inconsistent between the two groups. Thereby the authors have concluded that the parameters of the single-modal Weibull model are dependent on the fiber diameter, so that the model is inadequate to reproduce the strength size effect. On the other hand, Weibull parameters were found consistent between the two groups by excluding the data of 'large mirror zone' sample, which was defined as the sample around 10% mirror zone area of the fracture surface. What is more, the exclusion reduced the strength variance more drastically in the 'large diameter' group than in the 'small diameter' group, even though the 'large mirror zone' samples were found identical in the percentage between the two groups. The authors therefore conclude that diameter limitation to the 'small diameter' group level can lead to drastically less distributed strength values than the estimated strength through the Weibull scaling on the present Tyranno ZMI Si-Zr-C-O fiber.

Keywords

References

  1. E. E. Bloom, The challenge of developing structural materials for fusion power systems, J. Nuclear Mater. 258-263, 7-17 (1998) https://doi.org/10.1016/S0022-3115(98)00352-3
  2. H. Kaya, The applications of ceramic-matrix composites to the automotive ceramic gas turbine, Compos. Sci. Technol. 59, 861-872 (1999) https://doi.org/10.1016/S0266-3538(99)00016-0
  3. A. Hasegawa, A. Kohyama, R. H. Jones, L. L. Snead, B. Riccardi and P. Fenici, Critical issues and current status of SiC/SiC composites for fusion, J. Nuclear Mater. 283-287, 128-137 (2000) https://doi.org/10.1016/S0022-3115(00)00374-3
  4. A.-A. F. Tavassoli, Present limits and improvements of structural materials for fusion reactors - a review, J. Nuclear Mater. 302, 73-88 (2002) https://doi.org/10.1016/S0022-3115(02)00794-8
  5. R. H. Jones, L. Giancarli, A. Hasegawa, Y. Katoh, A. Kohyama, B. Riccardi, L. L. Snead and W. J. Weber, Promise and challenges of $SiC_f/SiC$ composites for fusion energy applications, J. Nuclear Mater. 307-311, 1057-1072 (2002) https://doi.org/10.1016/S0022-3115(02)00976-5
  6. W. Weibull, A statistical distribution function of wide applicability, J. Appl. Mech. 18, 293-297 (1951)
  7. S. van der Zwaag, The concept of filament strength and the Weibull Modulus, J. Test. Eval. 17, 292-298 (1989) https://doi.org/10.1520/JTE11131J
  8. D. M. Wilson, Statistical tensile strength of $Nextel^{TM}610$ and $Nextel^{TM}720$ fibres, J. Mater. Sci. 32, 2535-2542 (1997) https://doi.org/10.1023/A:1018538030985
  9. M. R. Gurvich, A. T. Dibenedetto and A. Pegoretti, Evaluation of the statistical parameters of a Weibull distribution, J. Mater. Sci. 32, 3711-3716 (1997) https://doi.org/10.1023/A:1018603118573
  10. V. Lavaste, J. Besson and A. R. Bunsell, Statistical analysis of strength distribution of alumina based single fibres accounting for fibre diameter variations, J. Mater. Sci. 30, 2042-2048 (1995) https://doi.org/10.1007/BF00353031
  11. Y. T. Zhu, W. R. Blumenthal, S. T. Taylor and T. C. Lowe, Analysis of size dependence of ceramic fiber and whisker strength, J. Amer. Ceram. Soc. 80, 1447-1452 (1997) https://doi.org/10.1111/j.1151-2916.1997.tb03002.x
  12. I. J. Davies and T. Ishikawa, Bundle to bundle variation of mean fiber radius for Tyranno LoxM Si-Ti-C-O fibers, J. Mater. Sci. Lett. 20, 505-507 (2001) https://doi.org/10.1023/A:1010912029618
  13. Y. Zhang, X. Wang, N. Pan and R. Postle, Weibull analysis of the tensile behavior of fibers with geometrical irregularities, J. Mater. Sci. 37, 1401-1406 (2002) https://doi.org/10.1023/A:1014580814803
  14. M. Shibuya, Tyranno fiber and Tyranno fiber reinforced composites, Fine Ceramics Report 11, 240-244 (1993) (in Japanese)
  15. T. Morimoto, Statistics on the strength of ceramic fiber bundle, Internat. J. Mater. Prod. Technol. 16, 22-31 (2001) https://doi.org/10.1504/IJMPT.2001.005390
  16. T. Morimoto, S. Nakagawa and S. Ogihara, Bias in theWeibull strength estimation of a SiC fiber for the small gauge length case, JSME Internat. J. Series A 48, 194-198 (2005) https://doi.org/10.1299/jsmea.48.194
  17. K. Kumagawa, H. Yamaoka, M. Shibuya and T. Yamamura, Fabrication and mechanical properties of new improved Si-M-C-(O) Tyranno fiber, Ceram. Engng Sci. Proc. 19, 65-72 (1998)