Additive manufacturing has allowed for the production of complex and mass customized geometries, but often at the expense of mechanical performance, a penalty which can be in part mitigated with the fabrication of composite parts. Thermoplastic structures fabricated with material extrusion additive manufacturing stand to be improved in terms of fracture toughness with the integration of continuous fibers. The present research program has investigated the production of a continuously reinforced filament to be used in open-source fused filament fabrication systems. Three different volume fractions of Kevlar fibers were incorporated into a polylactic acid (PLA) thermoplastic filament. It was observed that a 20% fiber volume fraction resulted in a doubling of the tensile strength relative to the unreinforced PLA parts. High-velocity impact tests were also performed on the reinforced printed thermoplastic material, and it was observed that the composite with the highest fiber volume fraction provided an impact energy resistance improved by a factor of four, relative to the plain PLA. The reinforced fibers have shown to restrain the penetration of the projectile at velocities similar to those that perforated the unreinforced PLA. The present work has demonstrated the production of printed composites without the need of modifying the extruding systems of a commercial 3D printer. This approach could represent an alternate and feasible process for producing continuously reinforced 3D-printed thermoplastic parts with utility for high-velocity impact applications.

增材制造允许生产复杂且批量定制的几何形状，但通常以机械性能为代价，这可以通过制造复合零件而部分减轻。通过材料挤出增材制造制造的热塑性结构在连续纤维集成的断裂韧性方面得到改善。本研究计划已经研究了连续增强长丝的生产，该长丝将用于开放源代码的熔融长丝制造系统。将三种不同体积分数的凯夫拉尔纤维掺入聚乳酸（PLA）热塑性长丝中。观察到，相对于未增强的PLA零件，纤维体积分数为20％导致抗拉强度增加了一倍。还对增强的印刷热塑性材料进行了高速冲击试验，并且观察到，纤维含量最高的复合材料相对于普通PLA而言，其抗冲击能量性能提高了四倍。增强纤维已显示出以与未增强PLA穿孔相似的速度抑制弹丸的渗透。本工作证明了印刷复合材料的生产，而无需修改商用3D打印机的挤出系统。这种方法可以代表一种替代且可行的方法，用于生产连续增强的3D打印的热塑性零件，并适用于高速冲击应用。并且观察到，相对于普通PLA，具有最高纤维体积分数的复合材料提供的抗冲击能量性提高了四倍。增强纤维已显示出以与未增强PLA穿孔相似的速度抑制弹丸的渗透。本工作证明了印刷复合材料的生产，而无需修改商用3D打印机的挤出系统。这种方法可以代表一种替代且可行的方法，用于生产连续增强的3D打印的热塑性零件，并适用于高速冲击应用。并且观察到，相对于普通PLA，具有最高纤维体积分数的复合材料提供的抗冲击能量性提高了四倍。增强纤维已显示出以与未增强PLA穿孔相似的速度抑制弹丸的渗透。本工作证明了印刷复合材料的生产，而无需修改商用3D打印机的挤出系统。这种方法可以代表一种替代且可行的方法，用于生产连续增强的3D打印的热塑性零件，并适用于高速冲击应用。增强纤维已显示出以与未增强PLA穿孔相似的速度抑制弹丸的渗透。本工作证明了印刷复合材料的生产，而无需修改商用3D打印机的挤出系统。这种方法可以代表一种替代且可行的方法，用于生产连续增强的3D打印的热塑性零件，并适用于高速冲击应用。增强纤维已显示出以与未增强PLA穿孔相似的速度抑制弹丸的渗透。本工作证明了印刷复合材料的生产，而无需修改商用3D打印机的挤出系统。这种方法可以代表一种替代且可行的方法，用于生产连续增强的3D打印的热塑性零件，并适用于高速冲击应用。