Failure analysis and statistical validation of fused filament fabricated PETG composite for transtibial prosthetics
摘要
This study investigates the mechanical behavior of fused filament fabrication (FFF) based carbon-fiber-reinforced polyethylene terephthalate glycol (CrF-PETG) composites for the development of transtibial prosthetic sockets (TtPS) and foot. A comprehensive experimental and statistical analysis was conducted to optimize process control parameters (PCP), specifically deposition nozzle diameter (DND) and internal filling design (IFD), to enhance mechanical performance. The mechanical properties—compressive strength (CS), impact strength (IS), and flexural strength (FS)—were assessed, with failure morphology analyzed using scanning electron microscopy (SEM). The results demonstrated a significant enhancement in mechanical properties with optimized PCPs. The highest CS of 47.34 MPa and IS of 35.94 kJ/m2 was obtained with a 0.4 mm DND and a grid (GD) IFD, making it suitable for weight-bearing and dynamic loading applications such as prosthetic foot. Similarly, the highest FS of 65.64 MPa was achieved with a 0.4 mm DND and a tri-hexagon (TH) IFD, indicating superior resistance to bending forces, critical for prosthetic socket applications. Statistical analysis validated the significance of DND and IFD on mechanical performance, with DND playing a dominant role in IS and FS, while IFD had a more pronounced effect on CS. The novelty of this study lies in the first-time optimization of CrF-PETG composites for TtPS and foot applications, addressing a critical gap in FFF-based prosthetic development. The integration of statistical modeling and experimental validation enhances the reproducibility and reliability of the findings.