Fibre damage in the manufacture of advanced three-dimensional woven composites

Fibre damage caused by the weaving of three-dimensional (3D) fabric preforms for advanced composite materials is investigated. A Jacquard loom was used to weave continuous fibreglass yams into a 3D orthogonal woven fabric. Samples of warp and through-thickness yams that form the 3D fabric were taken from the loom at different stages in the weaving process to examine for fibre damage and determine their residual tensile properties. It was discovered that the fibres are abraded against each other and the loom machinery during weaving, and the resulting abrasion damage and removal of sizing agent causes a reduction in yam strength of between 30 and 50% depending on the type of yam. Some fibres are also broken during weaving, and this causes a small reduction to the yam stiffness and contributes to the large loss in yam strength. The implication of these findings for the design of advanced 3D woven composites in structural applications is discussed. (C) 2003 Elsevier Ltd. All rights reserved.