Influence of fibre orientation on mechanical behaviour of Onyx-carbon fibre composites fabricated via additive manufacturing

Additive manufacturing has introduced new possibilities for fabricating composite materials with tailored mechanical properties, particularly through precise control of fibre orientation. This study explores the influence of carbon fibre reinforcement orientation on the mechanical performance of Onyx FR-A composites, manufactured using the Markforged FX20 printer. Mechanical tests, including tensile, compressive, open-hole tension (OHT), and interlaminar shear stress (ILSS) tests, were conducted on specimens with varying fibre orientations (0° and 90° relative to the loading axis). The findings demonstrate that fibre orientation plays a crucial role in determining material behaviour, with 0° orientations providing enhanced tensile and compressive strength compared to 90° orientations. Additionally, additive manufacturing enables the creation of complex geometries, such as OHT specimens, without secondary processes like drilling, which can damage fibres, offering significant advantages over traditional methods. The results offer critical insights into composite design for high-performance applications.