3D printing of continuous fiber reinforced cellular structural composites for the study of bending performance

Abstract

Optimization of 3D printing factors has been the underlying issue for the last decade. Herein, a 3D-printing procedure was operated to fabricate continuous fiber-reinforced composites in various shape-filled cellular structures based on Kevlar fiber and polylactic acid The efficient processing parameters in bending performance have been systematically studied, such as printing path, fiber orientation, infill density, cell length, and layer thickness. A three-point bending test revealed that, as the effective density increased, there was an irrefutable rise in strength and stiffness of CFRCs with different infill structures. Structural parameters like cell length could improve bending performance; this effect was evaluated by adjusting the fiber orientations along the stretching direction. Furthermore, a finite element model was developed, and its results were verified with the experimental results. The sample of the rhombus-filled cellular CFRCs with a layer thickness of 0.1 mm was found to have the highest bending strength and modulus of 53.61 MPa and 2728.41 MPa, respectively. Since mechanical behavior mostly depends on numerous microstructural factors, plenty of prototypes should be designed to achieve the required bending strength and flexural modulus—this work is a pattern guide to reduce the number of printed samples.