Abstract
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.
Similar content being viewed by others
References
O. Orringer, AFOSR TR 71 3098 (1971).
L. B. Greszczuk, AFML TR 71 231 (1972).
B. W. Rosen, Mechanics of Composite Strengthening, in “Fibre Composite Materials” (A.S.M., Cleveland, Ohio, 1965) pp. 37–75.
M. A. Sadowsky, S. L. Pu and M. A. Hussain, J. Appl. Mech. 34 (1967) 1011.
L. R. Herrmann, W. E. Mason and S. T. K. Chan, J. Composite Mat. 3 (1967) 212.
W. Y. Chung and R. B. Testa, ibid 3 (1969) 58.
E. M. De Ferran and B. Harris, ibid 4 (1970) 62.
J. R. Lager and R. R. June, ibid 3 (1969) 48.
P. D. Ewins, RAE TR 70007 (1970).
R. L. Foye, AIAA, 3rd Aerospace Sciences Meeting, N.Y., USA (1966) Paper 66-143.
T. Hayashi, 7th International Reinforced Plastics Conference, Brighton, UK, (1970) Paper 11.
P. D. Ewins and A. C. Ham, The Nature of Compressive Failure in Unidirectional Carbon Fibre Reinforced Plastics. To be published.
A. S. Argon, Fracture of Composites, in “Treatise on Materials Science and Technology”, Vol 1 (Academic Press, New York, USA, 1972) pp. 79–114.
R. L. Sierakowski, G. E. Nevill, C. A. Ross and E. R. Jones, J. Composite Mat. 5 (1971) 362.
P. D. Ewins, RAE TR 71217 (1971).
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.
D. Purslow and T. A. Collings, RAE TR 72096 (1972).
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.
A. Kelly, “Strong Solids” (Oxford University Press, 1966) pp. 150–55.
N. L. Hancox and H. Wells, Carbon Composite Technology Symposium (ASME), University of New Mexico, Albuquerque, N.M., USA. 37–53 (1970).
N. L. Hancox, Composites 2 (1971) 41.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Hancox, N.L. The compression strength of unidirectional carbon fibre reinforced plastic. J Mater Sci 10, 234–242 (1975). https://doi.org/10.1007/BF00540347
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00540347