Numerical simulating the flexural properties of 3D weft-knitted spacer fabric reinforced composites

Three-dimensional spacer fabrics due to their specific structural features have achieved significant importance to be used as highly effective technical textiles especially in composite manufacturing. Increasing applications of three-dimensional fabrics in technical fields as well as the high ability of knitting process in production of highly structured-knitted preforms made the researchers to be focused on finding novel structures with high potential application as the composite reinforcements in order to achieve some desired properties. Along with others researches, in this paper an especially structured three-dimensional spacer weft-knitted fabrics was produced on an electronic flat knitting machine, using 1680 denier high-tenacity polyester yarn. The fabrics samples were employed in thermoset composite manufacturing process using the epoxy resin. In order to investigate the mechanical behavior of the composite samples in term of their flexural performance, a three-point bending test was performed. For precise investigation, numerical simulation based on finite element method was also applied. Good correlation between the experimental and theoretical results showed such reasonable validity of the proposed model for simulating the mechanical behavior of the spacer-knitted reinforced composite under external bending loads.