Paper number 816

ISOTROPIC AND NEARLY ISOTROPIC FIBRE COMPOSITES

A. KELLY and L. N. McCARTNEY^*

The National University of Singapore, Kent Ridge Crescent, Singapore 119260
(address correspondence to Department of Materials Science and Metallurgy, University of Cambridge, Cambridge, CB2 3QZ)
*Centre for Collaborative Research, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153, Japan (address correspondence to Centre for Materials Measurement & Technology, National Physical Laboratory, Teddington, Middlesex, TW11 0LW, UK)

Summary

It has recently been demonstrated in some considerable detail that a fibre composite with isotropic elastic properties can be realised with a number of different arrangements of fibres. In all cases the volume fraction of fibres which can be introduced into the composite is limited. In the case of an isotropic arrangement the largest volume fraction which can be attained is about 50%. The elastic properties of this arrangement, which consists of two sets of fibres, one set parallel to cube edges and the other parallel to cube diagonals, is explored in detail. Its properties are compared with a more symmetric arrangement which is close to but not completely isotropic, namely, one in which fibres are arranged parallel to the six cube face diagonals. A very useful arrangement is that in which, for the first case, one of the sets of fibres parallel to cube edges is omitted. The properties of these isotropic and nearly isotropic fibre arrangements are compared with the properties of particulate composites.

Keywords

fibre-reinforced composites, effective properties, micromechanics, isotropic.