Flexural response of <scp>3D</scp> printed continuous carbon fiber reinforced photocurable polymer composites

Abstract

Abstract Additive manufacturing of continuous fiber‐reinforced composites facilitates complex geometries and optimized properties. Using robotics in 3D printing enables strategic fiber distribution and metered resin impregnation. This research seeks to characterize the properties of 3D printed fiber composites as a function of stacking sequence, including unidirectional ([0°] 18 and [90°] 18 ), cross‐ply ([90°/0°] 9 and [±45°] 9 ), and quasi‐isotropic ([0°/∓[20°/40°/60°/80°]] s ) layup schedules, and carbon fiber tow type (i.e., T1100, T800, and IM7). The geometric accuracy was evaluated by comparing the achieved and targeted panel dimensions, showing negligible differences and substantiating the translational potential of this additive manufacturing platform. Thermogravimetric analysis revealed the fiber volume fraction (ca. 50% irrespective of stacking sequence or fiber type) and resin residuals (remnant solid content after pyrolysis). Flexural samples were tested under quasi‐static conditions to investigate the influence of the fiber tow type and stacking sequence on the mechanical performance, exceeding previously reported 3D printed panels with thermoplastic and thermosetting matrices. Digital image correlation bolstered the flexural results by delineating the strain field, leading to additional insights about the flexural performance of the additive manufactured composites. The outcomes transcend the state‐of‐the‐art 3D printing of composite materials and accelerate their translational potential. Highlights Robotic 3D‐printed carbon fiber‐photocurable resin composites. 3D printing method results in repeatable geometric and thermogravimetric properties. Flexural properties were investigated as a function of fiber orientation and type. Digital image correlation quantified strain distribution in composite samples. Mechanical performance was compared with state‐of‐the‐art in literature.