The paper addresses the surface imperfections (openings in fibrous plies) and irregularity of the piercing pattern in structurally stitched multilayer carbon-fibre preforms. Each layer is a multiaxial multiply non-crimp fabric (NCF) with a non-structural stitching. The term “structural” presumes here that the stitching yarn does not only consolidate the plies (as the non-structural one does) but forms also a through-the-thickness (3D) reinforcement. Four stitching methods are studied: ordinary CNC-sewing, tufting, dual-needle, and curved needle techniques with multifilament yarns: aramide (60 or 120 tex) or glass (204 tex). In total, 14 stitching cases are investigated experimentally. It is observed that a non-negligible variability exists in the meso-level geometry of the reinforcement. The geometrical characterization provides important input data for analysis of the permeability and mechanical properties of the preforms.
|Journal||Advanced Composites Letters|
|Publication status||Published - 2006|
- Textile Composite
- quality analysis
- Structural Stitching
- geometrical characterisation