Journal of Materials Science

, Volume 10, Issue 2, pp 234–242 | Cite as

The compression strength of unidirectional carbon fibre reinforced plastic

  • N. L. Hancox


A simple compression test, suitable for quality control measurements on unidirectional carbon fibre composite, is described. The specimen, a plane bar, with aluminium end tabs attached, is compressed by applying shear forces over the ends. With either type 1 or type 2 treated fibre the failure mode is one of shear over a plane at approximately 45° to the fibre axis. With untreated type 1 material failure is due to delamination. The variation of the compression strength of treated material with fibre volume loading is linear, the values being considerably below those predicted by buckling theory. Increasing void content causes a steady decrease in compression strength, and off-axis strength values are above those given by the maximum work criterion. The present work supports the recently proposed view that the compression strength of unidirectional carbon fibre composites at room temperature is not governed by fibre buckling but is related to the ultimate strength of the fibre.


Compression Test Fibre Volume Compression Strength Fibre Axis Void Content 
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  1. 1.
    O. Orringer, AFOSR TR 71 3098 (1971).Google Scholar
  2. 2.
    L. B. Greszczuk, AFML TR 71 231 (1972).Google Scholar
  3. 3.
    B. W. Rosen, Mechanics of Composite Strengthening, in “Fibre Composite Materials” (A.S.M., Cleveland, Ohio, 1965) pp. 37–75.Google Scholar
  4. 4.
    M. A. Sadowsky, S. L. Pu and M. A. Hussain, J. Appl. Mech. 34 (1967) 1011.Google Scholar
  5. 5.
    L. R. Herrmann, W. E. Mason and S. T. K. Chan, J. Composite Mat. 3 (1967) 212.Google Scholar
  6. 6.
    W. Y. Chung and R. B. Testa, ibid 3 (1969) 58.Google Scholar
  7. 7.
    E. M. De Ferran and B. Harris, ibid 4 (1970) 62.Google Scholar
  8. 8.
    J. R. Lager and R. R. June, ibid 3 (1969) 48.Google Scholar
  9. 9.
    P. D. Ewins, RAE TR 70007 (1970).Google Scholar
  10. 10.
    R. L. Foye, AIAA, 3rd Aerospace Sciences Meeting, N.Y., USA (1966) Paper 66-143.Google Scholar
  11. 11.
    T. Hayashi, 7th International Reinforced Plastics Conference, Brighton, UK, (1970) Paper 11.Google Scholar
  12. 12.
    P. D. Ewins and A. C. Ham, The Nature of Compressive Failure in Unidirectional Carbon Fibre Reinforced Plastics. To be published.Google Scholar
  13. 13.
    A. S. Argon, Fracture of Composites, in “Treatise on Materials Science and Technology”, Vol 1 (Academic Press, New York, USA, 1972) pp. 79–114.Google Scholar
  14. 14.
    R. L. Sierakowski, G. E. Nevill, C. A. Ross and E. R. Jones, J. Composite Mat. 5 (1971) 362.Google Scholar
  15. 15.
    P. D. Ewins, RAE TR 71217 (1971).Google Scholar
  16. 16.
    I. K. Park, Tensile and Compressive Test Methods for High Modulus Graphite Fibre Reinforced Composites, Carbon Fibres, London, “Plastics and Polymers”, Supplement No. 5 (1971) Paper No. 23.Google Scholar
  17. 17.
    D. Purslow and T. A. Collings, RAE TR 72096 (1972).Google Scholar
  18. 18.
    S. W. Tsai, Strength Theories of Filamentary Structures, in “Fundamental Aspects of Fibre Reinforced Plastic Composites”, edited by R. T. Schwartz and H. S. Schwartz (Interscience, New York, 1968) pp. 3–11.Google Scholar
  19. 19.
    A. Kelly, “Strong Solids” (Oxford University Press, 1966) pp. 150–55.Google Scholar
  20. 20.
    N. L. Hancox and H. Wells, Carbon Composite Technology Symposium (ASME), University of New Mexico, Albuquerque, N.M., USA. 37–53 (1970).Google Scholar
  21. 21.
    N. L. Hancox, Composites 2 (1971) 41.Google Scholar

Copyright information

© Chapman and Hall Ltd. 1975

Authors and Affiliations

  • N. L. Hancox
    • 1
  1. 1.Process Technology Division, UKAEA Research GroupAEREHarwell, DidcotUK

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