A modified rule-of-mixtures for prediction of tensile strengths of unidirectional fibre-reinforced composite materials
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Measured ultimate tensile strengths in unidirectional fibre-reinforced composite materials have been observed to deviate from the linear predictions of the classical rule-of-mixtures relationship. The physical factors responsible are fibre-fibre interaction, inhomogeneous fibre distribution in the matrix and fibre misorientation to the loading direction. A recent modification to the classic rule-of-mixtures to account for fibre-fibre interaction has already resulted in good agreement between measured and predicted values of ultimate tensile strengths at high fibre volume fractions for Kevlar/epoxy composites. Additional modifications to the rule of mixtures to incorporate both fibre misorientation and inhomogeneous spread have been presented here. These modifications result in greater agreement between measured and predicted ultimate tensile strengths at low fibre volume fractions while retaining the accuracy of prediction at higher fibre volume fractions. Good agreement between measured and predicted values of inhomogeneous fibre spread were obtained at high fibre volume fractions. Furthermore, these additions to the classic rule-of-mixtures can be used to gauge the extent of each of the physical factors responsible for ultimate tensile strength reduction in unidirectional composite materials.
KeywordsTensile Strength Ultimate Tensile Strength Physical Factor Additional Modification Fibre Volume Fraction
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- 1.B. D. Agarwal and L. J. Broutman, “Analysis and Performance of Fiber Composites” (Wiley, New York, 1980).Google Scholar
- 2.R. M. Jones, “Mechanics of Composite Materials” (Scripta Book Company, 1975).Google Scholar
- 3.A. Kelly and N. H. Macmillan, “Strong Solids”, 3rd Edn, (Clarendon Press, Oxford, 1986) p. 240.Google Scholar
- 4.P. K. Mallick, in “Fiber-Reinforced Composite Materials: Manufacturing and Design” (Marcel Dekker, New York, 1988) p. 84.Google Scholar
- 5.D 3171–76 and D 3379-75, “Annual Book of ASTM Standards: Space Simulation; Aerospace Materials; High Modulus Fibers and Composites”, 15.03 (American Society for Testing and Materials, Philadelphia, PA, 1983).Google Scholar
- 8.K. G. Krieder and G. R. Leverant, Fl in “Advanced Fibrous Reinforced Composites”, Vol. 10 (Western Periodicals, N Hollywood, CA, 1966).Google Scholar
- 9.R. G. Carlson and D. S. Tomalin, ibid., p. 45.Google Scholar
- 10.F. R. Bonnano, ibid., p. 105.Google Scholar
- 12.S. S. Rangaraj, unpublished.Google Scholar