An investigation of the structure-property relationship of knitted composites

The tensile and compressive behaviours of knitted composites in the wale an d course directions were studied for their dependence upon knit architectur e and varying knit/structural parameters, such as loop length and stitch de nsity. Strength, modulus and strain-to-failure were investigated. In additi on, Poisson's ratio of the composites under tensile loading was also studie d. Post-failure examination was carried out on the test specimens using ste reo-optical and scanning electron microscopy to analyse their fracture mech anisms. It has been found that any change in the mechanical properties of t he knitted composites with respect to architecture and knit/structural para meters are broadly related to accompanying modifications to the state of th e microstructural imperfections, viz. fibre bending and fibre crossover jun ctions, and also to the relative fibre distribution along the two principal loading axes, in the knit structure.