Investigations into flexural behavior of additively manufactured short and continuous fiber CFRP composites

Flexural properties of the laminate composite are one of the important considerations in designing structural members of aerospace and automobile domains. In this study, the flexural properties of nylon-based short and continuous carbon fiber 3D-printed CFRP composite are investigated with a variation of volume fraction and raster orientation. Among the different fiber compositions with continuous fiber, the unidirectional CFRP with a high-volume fraction showed the highest bending stiffness of 16.667 GPa and flexural strength of 258 MPa, respectively. Furthermore, fracture surfaces of continuous CFRP are investigated using scanning electron micrographs to examine the different modes of failure behaviors under flexural load. Specifically, fiber pull-out and fiber breakage are the major failure phenomenon observed in the fracture surfaces of continuous fiber specimens. Few fiber kinking and fiber delamination are observed in cross-ply laminates of both high- and low-fiber volume fraction laminate composites, particularly in 90(0) layers. The degree of flexural properties anisotropy is determined by the quality of carbon fiber dispersion across the printed interfacial regions of the 3D-printed short and continuous fiber composites. The results revealed that raster orientations had a significant impact on the flexural properties of continuous fiber 3D-printed composites.