Additive manufacturing of woven carbon fibre polymer composites

A novel technique for the fabrication of woven composites using additive manufacturing (AM) is presented and evaluated. To-date fibre reinforced composites deposited by AM exhibit highly anisotropic properties as the individual layers do not interact, this study helps address this by printing of a 0/90 woven structure into one layer to aid in stress distribution. A fibre path generator was created utilising Gcode to emulate the weft-warp components of a woven construction using a continuous carbon fibre filament. This new pathing technique also allows for a woven structure to be integrated with features (such as notches) previously only possible through destructive machining processes. In order to evaluate the performance of the printed composites, open hole tensile studies were carried out in which 6 mm holes were routed into the composite structure and the resulting part's mechanical performance were compared with specimens which had been die punched as well as an unnotched control group. The latter exhibited strengths equivalent to 49% that of unnotched specimen. In contrast the specimens with woven holes exhibited strengths which were 44% higher, just 7% lower than the strength achieved for the unnotched specimens. Digital image correlation (DIC) analysis also demonstrated significantly reduced strain concentration around the printed hole perimeter, compared with that for the die punched hole.