Analytical procedure for the prediction of elastic properties of plain knitted fabric-reinforced composites

This paper presents an analytical method for predicting the elastic properties of plain-knitted fabric-reinforced composites. Firstly, a geometrical model suitable for expressing the orientation of knitted fabric has been identified. Equations have been developed for estimating the fibre content of the composite. The effects of yarn linear density and knitted fabric stitch density on the fibre content of the composite are predicted. Based on the laminated plate theory, a 'cross-over model' has been proposed. As the name suggests, this model considers the cross-over of curved yarns of knitted fabric. Owing to their curved fibre architecture, the knitted fabric composites are heterogeneous with resin and fibre-rich regions. The elastic properties of the composite were determined by combining the effective elastic properties of the curved yarns and the resin-rich regions. Elastic properties of knitted fabric composites with different fibre contents were computed. The analytical method has been validated by comparing one set of experimental results with the predictions. The applicability and limitation of this model have been discussed. Copyright (C) 1996 Published by Elsevier Science Limited.