EFFECT OF MESO-STRUCTURE CHARACTERISTICS ON MECHANICAL PROPERTY OF STITCHED COMPOSITES

The influences of the fibre waves on in-plane properties of stitched composite were studied through analyzing the meso-structure characteristics of stitched laminates. The five characteristics parameters were fibre wave angles, lengths and widths of wave regions, the diameters of stitch lines, the gaps between resins and fibres. The angles and widths of resin-rich areas of the composites with various stitch densities and stitch directions were measured and statistically estimated by image analytical software. The relationships among these five parameters were constructed and to be the basis of a representative unit cell. A three-dimensional finite element model was verified to predict the stiffness of stitched laminates with 0°, ±45°, 90° plies.