Mechanical Properties and Printable Curvature of Continuous Fiber Composites Fabricated by Embedded 3D Printing

Abstract The recently developed embedded printing technique enables composite fabrication by directing a laser beam onto the resin surface to cure it around continuous fiber bundles. This method allows for the production of composites with well‐aligned fibers, and minimal voids, and offers the ability to dynamically adjust matrix materials and control fiber volume fractions during printing. While previous studies have focused on proof‐of‐concept demonstrations, this study investigates the mechanical properties and printable curvatures along nonlinear pathways, both of which are essential for advancing 3D printing technologies for continuous fiber‐reinforced polymers (CFRPs). Uniaxial tensile tests are conducted to assess modulus, strength, and failure mechanisms, with different fiber volume fractions achieved by varying fiber thicknesses and filament spacing. To evaluate printability, circular filaments are printed at various speeds to determine the maximum printing curvature as a function of fiber volume fraction. The results enable the printing of continuous fibers with intricate patterns and composites featuring optimized printing pathways. Overall, this study deepens the understanding of the embedded printing process and offers valuable insights for further optimizing both the printing parameters and material selection. These findings can guide its future developments for broader applications in aerospace, automotive, construction, etc.