Paper number 457

NON-LINEAR BEHAVIOUR OF PLAIN WEFT-KNITTED CARBON FIBRE REINFORCED COMPOSITES

J. de Haan, R. Reber, J. Mayer and E. Wintermantel

Chair of Biocompatible Materials Science and Engineering, Department of Materials, Swiss Federal Institute of Technology (ETH) Zürich, Wagistrasse 23, 8952 Schlieren, Switzerland
http://www.biocomp.mat.ethz.ch/

Summary

Knitted fabrics offer a large deep-drawing potential. Characteristic for the textile structure is its interlooping yarns. A single loop consists of intermeshing regions and side limbs or legs. In this paper, the discussion of non-linear behaviour of knitted composites is focussed on the intermesh; in the intermesh the load is transferred between fibre bundles, due to the strong curvature, the stress state in the intermesh comprises a shear component. Due to the shear component the bending rigidity of the beam is decreased. The matrix dominates shear deformation, of which the influence is limited to the intermeshing area. Therefore, the deformation behaviour of knitted composites is defined as matrix directed for all in-plane directions.

Keywords

textiles, non-linearity, stress-strain behaviour, modulus prediction.