Perpustakaan Digital ITB

3D printed continuous carbon fiber reinforced polymers combine the geometric freedom of additive manufacturing with high load-bearing capability, yet their performance is limited by internal voids formed during layer-by-layer deposition and by strong dependence on fiber orientation. This study investigates how the 0° and 90° fiber orientations govern the tensile behavior of Onyx-based continuous carbon fiber composites printed on a Markforged Mark II, and evaluates whether post-printing compaction heat treatment can recover the strength lost to porosity. A finite element framework is also developed to predict the mechanical response and support the experimental findings. Specimens were fabricated following ASTM D3039 and tested in tension in both the as-printed and heat-compacted conditions, the latter consolidated at 145 °C and 2.5 MPa for 30 minutes. A macroscale model was built in Abaqus using a composite layup and the Hashin damage criterion, with experimentally measured moduli and tensile strengths combined with complementary properties from the literature, and validated against the measured stress–strain curves. Fiber orientation was the dominant factor: the as-printed 0° specimens reached 892.86 MPa and 70,828.7 MPa in strength and modulus, roughly 38 times stronger and 28 times stiffer than the 90° specimens. Compaction improved both directions but benefited the matrix-dominated 90° orientation most, raising its strength by about 75% and stiffness by about 170%, compared with only 7% and 7% for the 0° direction, thereby narrowing the anisotropy. The finite element model reproduced the experiments with errors below 2% in all cases and correctly captured the fiber- and matrix-dominated failure modes, confirming that a Hashin-based macroscale model can reliably represent 3D printed continuous carbon fiber composites across orientations and processing conditions.