Journal of Materials Science

, Volume 29, Issue 24, pp 6561–6574 | Cite as

An end-effect model for the single-filament tensile test

  • E. G. Stoner
  • D. D. Edie
  • S. D. Durham


The effect of cross-sectional shape on tensile strength of pitch-based carbon fibres was investigated by extensive single-filament testing. For this study, round and trilobal pitch-based carbon fibres were produced at similar processing conditions. The application of a variety of distributions, including the simple Weibull distribution, to the strength data indicated two sources of failure, one source being the accentuation of end effects at short gauge lengths. A new mixed distribution, the end-effect distribution, was proposed to account for these effects and applied to the experimental data. The end-effect model provided an excellent description of the strength distributions of all fibres studied. The end-effect distribution is not complex and is based on sound physical assumptions. It quantifies a recognized inadequacy of the test method which has not previously been accounted for, and it allows separation of end effects from the true fibre strength distribution. The results indicate that end effects can be an important concern for gauge lengths as long as 40 mm. Use of this model revealed that, in the absence of end effects, all fibres failed due to macroscopic flaws; thus, varying the fibre geometry does not result in an unusual failure mechanism. However, the tensile strengths of the non-circular fibre were found to be less dependent on fibre size. Thus, non-circular fibres can be produced at higher mass flow rates, decreasing filament breakage and increasing process conversions.


Tensile Strength Mass Flow Rate Gauge Length Fibre Strength Strength Distribution 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    J. B. Jones, J. B. Barr and R. E. Smith, J. Mater. Sci. 15 (1980) 2465.CrossRefGoogle Scholar
  2. 2.
    D. D. Edie, N. K. Fox, B. C. Barnett and C. C. Fain, Carbon 24 (1986) 477.CrossRefGoogle Scholar
  3. 3.
    H. E. Gainey, D. D. Edie, J. M. Kennedy and C. C. Fain, “Carbon 88”, Proceedings of the Seventh International Carbon Conference, Newcastle, UK edited by B. McEnaney and T. J. Mays (IOP, Bristol, 1988) p. 494.Google Scholar
  4. 4.
    E. G. Stoner, PhD dissertation, Clemson University, Clemson, SC (1991).Google Scholar
  5. 5.
    ASTM Standard, D3379-75, Reapproved 1989 (American Society for Testing and Materials, Philadelphia, PA).Google Scholar
  6. 6.
    J. W. Hitchons and D. C. Phillips, Fibre Sci. Technol. 12 (1979) 217.CrossRefGoogle Scholar
  7. 7.
    C. P. Beetz, Jr. ibid. 16 (1982) 45.CrossRefGoogle Scholar
  8. 8.
    H. D. Wagner and S. L. Phoenix, J. Compos. Mater. 18 (1984) 312.CrossRefGoogle Scholar
  9. 9.
    W. Nelson, “Applied Life Data Analysis” (Wiley, New York, 1982).CrossRefGoogle Scholar
  10. 10.
    K. K. Phani, J. Mater. Sci. 6 (1987) 1176.Google Scholar
  11. 11.
    Idem, ibid. K. K. Phani, J. Mater. Sci. 23 (1988) 1189.CrossRefGoogle Scholar
  12. 12.
    C. A. Johnson, in “Fracture Mechanics of Ceramics 5” edited by R. C. Bradt, A. G. Evans, D. P. H. Hasselman and F. F. Lange (Plenum Press, New York, 1985) pp. 365–86.Google Scholar
  13. 13.
    C. P. Beetz, Jr, Fibre Sci. Technol. 16 (1982) 81.CrossRefGoogle Scholar
  14. 14.
    L. S. Singer, US Pat. 4005 183 (1977).Google Scholar

Copyright information

© Chapman & Hall 1994

Authors and Affiliations

  • E. G. Stoner
    • 1
  • D. D. Edie
    • 1
  • S. D. Durham
    • 2
  1. 1.Department of Chemical Engineering and Center for Advanced Engineering Fibers, Earle HallClemson UniversityClemsonUSA
  2. 2.Department of StatisticsUniversity of South CarolinaColumbiaUSA

Personalised recommendations