The effect of binder path on the tensile properties and failure of multilayer woven CFRP composites

An investigation has been carried out on the in-plane tensile properties of two orthogonally woven structures with different binder paths. Measurement s were made along both the longitudinal (warp) and transverse (weft) axes o n samples manufactured from two commercially available carbon fibres which are known to have different resistance to fibre damage induced through weav ing. In general, this research revealed that the more damage-resistant fibr e produces composites with higher strength and stiffness. It was also found that, independent of the fibres used, the in-plane fibre yarns in the stru cture with the longer binder path are less crimped and this, by and large, translates to better or unchanged tensile modulus, strength and strain-to-f ailure. In addition to fibre fractures, the superior strength of this compo site was also observed to promote an extensive amount of longitudinal split ting, thus resulting in a relatively large failure zone. In the structure w ith the shorter path length where the in-plane fibres are more crimped, fai lure is due predominantly to fibre fractures. Groups of fibres are pulled o ut during failure of both structures, despite good fibre wetting and fibre/ matrix adhesion having been achieved with either fibre. (C) 2000 Elsevier S cience Ltd. All rights reserved.