Fatigue of 3D textile-reinforced composites

The fatigue of carbon fibre reinforced plastics - A review

“…Industrially, the use of a 3D preform greatly simplifies the out-of-autoclave (RTM) manufacturing cycle, saving time and money [138]. A through-thickness fibre reinforcement, such as 3D woven, stitched, tufted, z-anchor or z-pinned, as referenced by Mouritz [139], improves considerably, the interlaminar fracture toughness [140], the damage tolerance, the impact resistance, and it limits the propagation of macro-delaminations [141] as compared to 2D material. However, the in-plane properties of composites are lower than those of straight fibre engineering composites.…”

“…3D woven composites are standard fabrics with fibres running in the x-(warp) and y-(weft) in-plane directions, with a z-yarn binding the fabric layers. There are two main types of 3D woven composites: interlock fabric, where the z-binder is interlaced with the in-plane yarns, and orthogonal fabric, where the z-binder holds in place the entire stack of 2D fabrics, thus avoiding crimp and maximising the in-plane stiffness [139]. Carvelli et al [147] showed that there is a dependency of these composites on the loading direction (when comparing 2D and 3D wovens) [0, 90] s orthogonal CFRP in both warp and weft directions and tested in (T-T) fatigue.…”

“…Sewing methods vary from the use of simple orthogonal needles to robotic machines with needles working at different angles simultaneously [149]. The microstructures created by the stitch-14 ing process influence the monotonic mechanical properties, and the final 3D stitched composites sometimes display better, sometimes worse moduli and failure strengths as compared to 2D composites [139,142,149,150]. There is nevertheless, little doubt that the delamination toughness [151] and impact resistance [152] always improve through stitching.…”