Mechanical behaviour of plain-knit reinforced injected composites: Effect of inlay yarns and fibre type

This paper investigates the effect of inlay yarns and fibre type (E-glass, basalt, carbon) to improve the mechanical behaviour of plain knit reinforced composites (epoxy matrix). The tensile behaviour of the dry reinforcement was investigated in the wale and course-directions and has shown that the course-wise deformation is drastically reduced whereas the strength is strongly increased when inlay yarns are included. Fibre type has a weak effect on deformation and strength. For the composite material, processed by Liquid Composite Moulding, the carbon fibre reinforcement gives always the best results whatever the testing direction. Inlay yarns decrease the 0° mechanical properties, whereas 45° and 90° are increased. Moreover a quasi-isotropic behaviour is obtained when using two inlay yarns, irrespective of the fibre types.