Abstract
It is demonstrated that Raman spectroscopy is a powerful technique for the analysis of the relationship between structure and deformation processes in both high-performance fibres and fibre-reinforced composites. It is shown that Raman spectroscopy can be used to follow molecular deformation processes in Kevlar 49 aramid fibres. The strain dependence of the 1610 cm-1aramid Raman band is examined in detail and it is shown that there are local variations of fibre strain in deformed fibres. The shift of the same band in a high-volume fraction uniaxially-aligned composite is analysed and it is found that there are significant variations in local fibre strain due to imperfections in the composite. The distributions of axial fibre strain have also been mapped in a 4-hamess satin weave Kevlar 49/epoxy composite and it is demonstrated that there are complex distributions of local fibre strain that follow the pattern of the repeat unit of the woven structure. The power of the Raman technique to follow composite micromechanics is therefore demonstrated.
Get full access to this article
View all access options for this article.