Fibre fragment distribution in a single-fibre composite tension test

Single fibre fragmentation tests are performed for brittle fibres with Weib ull strength distribution and different surface treatments. The fragmentati on process is modelled and closed-form expressions for break spacing distri bution are obtained. The model accounts for the effect of finite fibre leng th on the initial fragmentation as well as for break interaction on the adv anced fragmentation stage. It is assumed that the exclusion zone due to fib re-matrix interface failure and stress recovery in the fibre is Linearly de pendent on the applied load. This assumption is validated experimentally. T he derived theoretical average fragment length dependence on applied load i s used to determine the fibre strength distribution parameters and the effe ctive interfacial shear stress for carbon/epoxy single fibre composites wit h different fibre surface treatment and for glass/vinylester single fibre c omposite. Fragment length distribution is predicted for several load levels . Predictions are in good agreement with experimental data. (C) 2001 Elsevi er Science Ltd. All rights reserved.