Mechanical behavior and failure mechanisms of FDM-printed PETCF-15 composites: An experimental and finite element study

This experimental study focuses on exploring the mechanical characteristics and characterization of fractured surface of polyethylene terephthalate with 15% carbon fiber (PETCF-15) composite in fused deposition modeling (FDM) process. Extrusion temperature, printing speed, layer thickness and raster angle are considered in this study. Taguchi’s design of experiments (L9) is used to perform experiments considering four process parameters: extrusion temperature (275–285°C,), layer thickness (0.1–0.3 mm), print speed (50–150 mm/s), and raster angle (0°–90°). The tensile testing performed in this work is in accordance with the standard tests prepared in the shape of dog-bone style. The printed PETCF-15 specimens exhibited the maximum tensile strength 62 N/mm 2 , a yield strength of 15.81 N/mm 2 and maximum strain value of 10.9 %, as determined from the experimental results. The weighted grey Taguchi method is used to determine the optimum parametric setting values that would correspond to maximum tensile strength, yield strength, and elongation at break. The tests revealed that the best combinations are extrusion temperature of 275°C, print speed of 50 mm/s, layer thickness of 0.1 mm with the raster angle at 0°. The extrusion temperature (37.67%) and raster angle (49.88%) are identified as the most influential parameters affecting the grey relational grade, as determined through grey relational analysis. The experimental results obtained were verified with finite element analysis using ABAQUS. Fracture surfaces after tensile tests are analyzed using a scanning electron microscopy (SEM) that allows understanding of failure modes and the microstructure of the fractured surface. The strong correlation between experimental, numerical, and microstructural results validates the robustness of the approach and confirms the potential of optimized PETCF-15 components for high-performance structural applications in the aerospace and automotive sectors.