Compressive failure mechanisms in multi-fibre microcomposites

Abstract

Understanding the microscopic mechanical behaviour of carbon fibre composites is essential in the analysis of the compressive response of unidirectional carbon fibre composites. Many analytical models have been proposed to predict the compressive strength of this class of materials, which combined with the experimental data existing in the literature, provide a relatively good understanding of this topic. Some fundamental issues, however, still remain open, such as the effect of a compressive fibre break or discontinuity on its surrounding intact fibres, or the effect of fibre/matrix interfacial properties. The present paper is an attempt to highlight the aspect of compression by employing multi-fibre model geometries. Then the FE method is used to validate/interpret the experimental results. The experimental and numerical findings suggest that compressive failure of high modulus carbon fibre/epoxy composites is mainly controlled by the compressive response of the carbon fibres themselves.