An investigation of the structure-property relationship of knitted composites

The tensile and compressive behaviours of knitted composites in the wale and course directions were studied for their dependence upon knit architecture and varying knit/structural parameters, such as loop length and stitch density. Strength, modulus and strain-to-failure were investigated. In addition, Poisson¿s ratio of the composites under tensile loading was also studied. Post-failure examination was carried out on the test specimens using stereo-optical and scanning electron microscopy to analyse their fracture mechanisms. It has been found that any change in the mechanical properties of the knitted composites with respect to architecture and knit/structural parameters are broadly related to accompanying modifications to the state of the microstructural imperfections, viz. fibre bending and fibre crossover junctions, and also to the relative fibre distribution along the two principal loading axes, in the knit structure.