Citation:
Colin de Verdiere M, Pickett Anthony K, Witzel V. (2007) ECCOMAS Thematic Conference on Mechanical Response of Composites, 12-14 Sept 2007, Porto Portugal
Abstract:
This paper examines the effectiveness of tufting in enhancing the through the
thickness properties of non crimped fabrics. The response of tufted and untufted
carbon/epoxyn on crimped fabric composites produced using resin infusion is
investigated in axial tension and compression and cyclic [±45] loading. The out-
of-plane response is studied in mode I and mode II delamination tests. Tufted
material has significantly higher delamination resistance and lower in plane
properties in tension and compression. Tufted and untufted non crimp fabric
composites have similar response in shearin terms of both plastic strain and
strength. Optical strain measurements allowed monitoring of the two dimensional
damage field incyclic experiments. Damage tends to be localised in untufted
specimens, where as it becomes more uniform across the width of specimens with
tufts. Material models for untufted and tufted non crimped fabric composites
simulating both non-linear in-plane behaviour and delamination damage were
developed. Material parameters were estimated from experimental results, and
both material submodels were implemented in a commercial explicit finite element
code which allows the in corporation of delamination behaviour using cohesive
interface elements. A comparison of experiments and finite element model results
simulating coupons verified the implementation of the models