Performance evaluation of fatigue behavior in extrusion-based functionally graded materials

The present study examined the fatigue life behavior of functionally graded additive manufacturing (FGAM) parts fabricated using "Material Extrusion" (MEX). It reveals the potential of FGMs for designing and improving the mechanical behavior of fabricated structures. For experimentation, a blend of polylactic acid (PLA) and thermoplastic polyurethane (TPU) are used as raw materials. The analysis of variance (ANOVA) statistical method is adopted to analyze the effect of the input parameters such as layer height (LH), extrusion multiplier (EM), bed temperature (BT), and extrusion temperature (ET) on the fatigue performance of FGAM specimens. From this, a set of parametric combinations consisting of LH of 1.5 mm, EM of 1.2%, and BT of 70 & DEG;C is found to be the best possible solution. Intuitively, the associated S-N curve at various stress levels is generated from the obtained set of parameters. Eventually, the recorded results demonstrated that the fabricated specimens exhibit superior performance in any working environment. Moreover, the novelty lies in the fatigue behavior study of FGAM structures which has never been attempted.