Effect of Stitches on the Permeability of Interbundle Channels in Stitched Fabrics

Stitched multilayer fabrics have drawn increasing attention as reinforcing materials for high performance composites due to their integrity and wide variety. In this paper, the focus is on the effect of stitches on the equivalent permeability of interbundle channels, which is inves tigated systematically through numerical simulation of Navier-Stokes equations and expressed as the value of K/K0. The results show that stitches may dramatically affect the permeability of interbundle channels, even if stitch size is relatively small. Thus, this effect has to be considered when establishing an effective permeability model for stitched fabrics. The nu merical simulation results also suggest that the effect of stitches is quite different for a different stitch size, off-center position, slope, array, distribution density, and average Darcy velocity in fiber bundles. Changes in K/K0with these parameters are discussed.