Abstract
In the study of fracture processes in composite materials, the interactions between broken and intact fibres are of critical importance. Indeed, the redistribution of stress from a failed fibre to its unfailed adjacent neighbours, and the stress concentration induced in these, determine the extent to which a break in one fibre will cause more breaks in neighbouring fibres. The overall failure pattern is a direct function of the stress concentration factors. In this paper we use laser micro-Raman spectroscopy to study the extent of stress transfer and redistribution caused by fibre fracture in two-dimensional Kevlar 149 based microcomposites. The strain along the fibres was mapped at different levels of load, and specimens with different inter-fibre distances were used to study the fibre content effect. The experimental stress concentration factors were compared with values predicted from various theoretical models. The stress concentration factors generally agreed with those literature models that include interfibre distance and matrix effects. The overall failure pattern was found not to be a direct function of the stress concentration factors in this system, as fracture propagates from fibre to fibre even at large interfibre distances, and is apparently accompanied by relatively low values of the stress concentration factors. The ‘critical cluster size’, beyond which final fracture of the composite occurs in a catastrophic manner, was found to be larger than five adjacent fibre breaks in the present system, for all interfibre distances studied.
Similar content being viewed by others
References
H. D.Wagner and A.Eitan, Appl. Phys. Lett. 58 (1991) 1033.
, Composites Science and Technology, 46 (1993) 353.
H. E.Daniels, Proc. Roy. Soc. London A183 (1945) 404.
J. M. Hedgepeth, NASA TN D-882 (1961).
J. M.Hedgepeth and P. Van Dyke, J. Compos. Mater. 1 (1967) 294.
W. B. Fichter, NASA TN D-5453 (1969).
D. G.Harlow and S. L.Phoenix, J. Compos. Mater. 12 (1978) 195.
12 (1978) 314.
R. E.Pitt and S. L.Phoenix, Int. J. Fracture 20 (1982) 291.
22 (1983) 243.
R. L.Smith, S. L.Phoenix, M.Greenfield, R. B.Henstenburg and R. E. Pitt, Proc. Roy. Soc. London A388 (1983) 353.
H.Fukuda and K.Kawata, Fukugo Zairyo Kenkyu (Comp. Mater. Struct.) 3 (1974) 21.
9 (1976) 189.
10 (1977) 53.
J. N.Rossettos and M.Shishesaz, J. Appl. Mech. 54 (1987) 723.
M. G.Bader, R. L.Smith, M. J.Pitkethly, Proc. Sixth Intern. Confer. on Composite Materials (ICCM-6) & Second Europ. Confer. on Composite Materials (ECCM-2) (F. L. Matthews, N. C. R. Buskell, J. M. Hodgkinson, J. Morton, Eds), 20–24 July, 1987, London (Elsevier Applied Science, London, 1987), Vol. 5 (1987) 481.
D. A.Clarke and M. G.Bader, Vol. 5, (1987) 382.
, in Proc. 7th Intern. Confer. on Composite Materials (ICCM-7) 25–28 August, 1989, Beijing (Eds: Wu Yunshu, Gu Zhenlong, and Wu Renjie, Intern. Acad. Publish., Beijing, Pergamon Press, Oxford, UK, 1989), Vol. 2. p. 79.
L. C.Wolstenholme and M. G.Bader,, Vol. 2, p. 84.
L. C.Wolstenholme and R. L.Smith, J. Mater. Sci. 24 (1989) 1559.
M. R.Nedele and M. R.Wisnom, Composites Science and Technology 51 (1994) 517.
N.Melanitis, C.Galiotis, P.Tetlow and C.Davies, J. Mater. Sci. 28 (1993) 1648.
R. J. Young, in Polymer Surfaces and Interfaces II (W. J. Feast, H. S. Munro, R. W. Richards, Eds), John Wiley & Sons (1993), pp. 131–159.
L.Schadler, C.Laird, N.Melanitis, C.Galiotis and J.Figueroa, J. Mater. Sci. 27 (1992) 1663.
H. D.Wagner and L. W.Steenbakkers, 24 (1989) 3956.
H. D.Wagner, M.Rubins and G.Marom, Polym. Compos. 12 (1991) 233.
R.Gulino, P.Schwartz and S. L.Phoenix, J. Mater. Sci. 26 (1991) 6655.
Z.-F.Li, D. T.Grubb and S. L.Phoenix, J. Mater. Sci. Lett. 13 (1994) 1720.
K. M.Atallah and C.Galiotis, Composites 24 (1993) 635.
B.Yavin, H. E.Gallis, J.Scherf, A.Eitan and H. D.Wagner, Polymer Composites 12 (1991) 436.
H. D.Wagner, in “Application of Fracture Mechanics to Composite Materials” (K. Friedrich, Editor, R. B. Pipes, Composite Materials Series Editor), Composite Materials Series 6, Elsevier Science Publishers B. V., Amsterdam, 1989, pp. 39–77.
L. W.Steenbakkers and H. D.Wagner, J. Mater. Sci. Lett. 7 (1988) 1209.
Author information
Authors and Affiliations
Additional information
Visiting Stein Fellow at Drexel University, July-September 1994.
Rights and permissions
About this article
Cite this article
Wagner, H.D., Amer, M.S. & Schadler, L.S. Fibre interactions in two-dimensional composites by micro-Raman spectroscopy. JOURNAL OF MATERIALS SCIENCE 31, 1165–1173 (1996). https://doi.org/10.1007/BF00353095
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/BF00353095