3D Translaminar and Textile Reinforcements for Composites

Abstract

AbstractThe group of translaminar‐reinforced composites, which includes stitched and Z‐pinned materials, requires additional manufacturing step (insertion of a stitch thread or Z‐pin) after the in‐plane fiber architecture has been already formed. This is why this group suffers from in‐plane fiber damage, distortions of the fiber architecture and the formation of resin‐rich zones in the vicinity of each stitch or Z‐pin. These negative effects may considerably reduce in‐plane elastic moduli but most significantly reduce in‐plane tension and compression strengths and fatigue resistance. The group of unitary (single‐ply) 3D textile reinforcements includes 3D weaves, 3D braids and 3D warp knits. The principal common feature of all preforms from this group is, that each of them is produced in a single manufacturing step, using either traditional or specialty textile machines. Owed to this feature, unitary 3D textile preforms can be used in a composite fabrication process as‐manufactured, thus greatly simplifying preform handling and resin infusion steps. Comparative analysis of various methods of 3D reinforcement for composites shows that the differences in the processes and machines strongly influence the differences in the reinforcement architectures and, consequently, strongly reflect on mechanical properties of the resulting composites. This is illustrated by experimental data on the in‐plane and out‐of‐plane mechanical properties of 2D weave laminates and composites reinforced with a single‐ply of 3D interlock weave or 3D orthogonal non‐crimp weave.