A Homogenised Material Approach to Predict Fatigue Life of Additively Manufactured PLA with Different In-fill Levels

This study presents a novel fatigue life prediction method for plain and notched polylactide (PLA) structures manufactured with different in-fill levels via additive manufacturing. The proposed method models additively manufactured PLA with internal voids as a continuous, homogeneous, linear-elastic, and isotropic material. The effect of these voids is represented by an equivalent crack, whose size is related to the void size. This approach provides a practical and accurate way to estimate the fatigue life of both plain and notched components, even when manufactured with different in-fill levels. The predicted fatigue lives agree with the experimental results obtained from specimens in different raster angles and in-fill levels.