A comprehensive fatigue analysis of high performance polyetherimide parts fabricatedusing extrusion-based additive manufacturing

This paper investigates the fatigue behavior of high-performance polyetherimide components manufactured via MEX-AM, focusing on the influence of key process parameters. Thirty configurations were tested under four load levels, and fractographic analysis was conducted to study crack initiation and propagation. Building direction proved critical, with edge-printed specimens showing up to 2.4 times longer fatigue life under low loads than flat-printed ones. Sparse configurations, despite lower mass, achieved similar or even superior specific performance compared to solid ones. For example, X-Flat-0.25 mm doubled the fatigue life of the best solid specimen under low loads with a 24% weight reduction, while X-Flat-0.75 mm achieved a 44% mass saving with only a 15.5% reduction in fatigue life. These results demonstrate the potential of optimized sparse designs for lightweight, high-performance MEX-AM parts.