Tensile property evaluations of 3D printed continuous carbon fiber reinforced thermoplastic composites

Continuous carbon fiber composites can be printed using 3D printers. Many studies detailing the mechanical properties of such 3D printed composites have been published, all of which employed a conventional tensile specimen configuration with surface resin layers. In the present study, 0°, 90°, ±45°, and lay-up direction type specimens have been designed for 3D printed composites without surface layers. Both conventional and newly designed specimens with serpentine folded fiber bundles were fabricated and investigated experimentally using a 3D printer. The lay-up direction specimen was fabricated using 800 layers. The specimens without the serpentine folded fiber bundles were experimentally shown to be adequate for tensile tests. The lay-up direction specimen had the lowest strength and stiffness, which appears to be related to its surface roughness.