Approach to net-shape preforming using textile technologies. Part I: edges

Considering cost-effective fibre-reinforced plastic (FRP) parts manufacture d by resin transfer moulding (RTM) technologies, net-shape preforms can con tribute to mechanical post treatment free manufacturing, hence reducing cyc le-time and cost. In addition to this, RTM specific problems, such as fibre pinching when closing the tool can be avoided. The wide range of textile t echnologies used for FRP parts offers various possibilities to achieve net- shape parts within the preforming process including bores or inserts (see p art II). The potential of the presented technologies is evaluated and discu ssed. Apart from standardised testing methods, a new side-impact testing wa s specially designed for determining the in-plane damage-tolerance of net-s hape manufactured FRP parts. Folding to net-shape shows poor quality but im proves mechanical properties. Rim-protections with braided inserts or over- edge stitching technologies which provide exact preform dimensions, improve d mechanical performance. Especially side-impact tolerance or in-plane dama ge tolerance was increased. Ultra-sonic testing was successfully applied to visualise the differences in damage tolerance and propagation between thes e new rim technologies. (C) 2000 Elsevier Science Ltd. All rights reserved.