9 research outputs found
Fiber Volume Fraction around Stitch in NCF Composites
AbstractThe aim of this paper is to compute the variations of fiber volume fraction around stitches in multi-axial multi-ply Non-Crimp Fabric (NCF) composites. The microstructure of NCF composites are investigated experimentally using scanned images. Observations show that the stitch yarn forces the fibers to deviate from their straight alignment which leads to the creation of crack-shaped defects or continuous channels result from connecting and merging of collinear crack-shaped defects. Another observation is that the fibers are compacted in the fiber distorted region. The path of fibers is then simulated with a third order polynomial and linear functions and a two-variable fiber volume fraction function is obtained at last. The function is able to predict the fiber volume fraction in any point in fiber distorted region