Analysis of Open‐Hole Tensile Characteristics of Additively Manufactured Continuous Glass Fiber/Onyx Composites

ABSTRACT The development of additively manufactured continuous fiber‐based polymer composites has received remarkable attention in developing next‐generation composite materials for numerous structural and non‐structural applications. The present study used an FDM‐based 3D printer to fabricate continuous glass fiber/Onyx composites (with and without holes) utilizing three infill patterns (solid, triangular, and gyroid). The open‐hole tensile properties of the composites were evaluated under quasi‐static tensile loading. The initiation and propagation of damage during testing were captured and analyzed using DIC. For specimens with holes, triangular infill provided the highest tensile strength (183 MPa), followed by solid (172 MPa) and gyroid patterns (167 MPa). The solid infill exhibited the highest tensile strength (278 MPa) for specimens without a hole, followed by triangular (264 MPa) and gyroid (252 MPa) infill patterns. For the composite with a hole, the gyroid infill exhibited the highest specific stiffness (735 MPa/g), followed by 720 and 700 MPa/g for triangular and solid infill, respectively. DIC results depict infill patterns, and stress concentrators significantly influence the damage initiation and propagation in the composites. Fractographic analysis revealed that composites with holes and solid infill patterns primarily failed due to longitudinal splitting at the gauge center. In contrast, those with gyroid and triangular infill patterns exhibited lateral failure.