Ductility in composites: Influence of ply-cuts on the flexural behavior of carbon fibre reinforced polymer (CFRP)

Discontinuous reinforcement phases are often observed in natural materials, such as nacre. The aim of this study is to introduce a degree of 'pseudo-ductility' to fibre reinforced polymer materials by exploiting such discontinuities. The work presented takes the principle of discrete material sections and applies it in the form of ply cuts to a carbon fibre reinforced polymer. A variety of specimen designs were tested which encompassed the principles taken from the architecture of nacre. Four point bend flexural testing was carried out and the failure processes investigated. It was identified that the ply end to ply end geometry, typically resulting in a resin pocket, is very important in achieving sequential failure of a conventionally brittle material.