Deshmukh et al. Res. Trends Int. J. Technol. Innov., July - September 2026, 1 (3) : 9-16
1Department of Mechanical Engineering, College of Engineering Pune, Pune, India; 2Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai, India
Article History
Accepted : 19 Jun 2026
Published : 10 Jul 2026
Publication Issue
Volume 1, Issue 3
July - September 2026
Page Number9–16
Fused deposition modelling introduces anisotropic mechanical behaviour that complicates fatigue-life prediction for load-bearing 3D-printed components. This study characterises the S-N fatigue curve of PLA specimens printed at three raster orientations (0, 45 and 90 degrees) under fully reversed cyclic loading, and fits a modified Basquin model incorporating a raster-orientation correction factor. The 45-degree raster orientation showed the highest fatigue endurance, withstanding 38 percent more cycles at a given stress amplitude than the 90-degree orientation, and the corrected model predicted experimental fatigue life within 12 percent average error.
Keywords - fused deposition modeling, fatigue analysis, PLA, additive manufacturing, S-N curve
Fused deposition modelling parts exhibit layer-dependent anisotropy that is well documented for static strength but comparatively under-characterised for fatigue behaviour, which governs the service life of parts subject to repeated loading such as functional brackets and enclosures.
Dogbone specimens were printed in PLA at 0, 45 and 90-degree raster orientations relative to the loading axis and subjected to fully reversed axial fatigue testing across five stress amplitude levels, with cycles to failure recorded for each of 45 specimens (15 per orientation), and a modified Basquin S-N model fitted incorporating a raster-angle correction term.
The 45-degree raster orientation exhibited the highest fatigue endurance, sustaining 38 percent more cycles than the 90-degree orientation at an equivalent stress amplitude of 18 MPa, while the 0-degree orientation performed intermediately. The corrected Basquin model predicted fatigue life within an average of 12 percent of experimental values across all three orientations, compared with 31 percent average error for the uncorrected isotropic model.
Raster orientation materially affects fatigue life in FDM-printed PLA parts, and orientation-corrected S-N models substantially improve prediction accuracy for design purposes. Future work will extend the correction framework to fibre-reinforced filaments.
[1] Basquin O. H., The exponential law of endurance tests, ASTM Proceedings, 1910. [2] Afrose M. F. et al., Effects of part build orientations on fatigue behaviour of FDM-processed PLA, Progress in Additive Manufacturing, 2016.
© 2026 The Author(s). Published by IJEIA Editorial Office. This is an open access article under the Creative Commons Attribution 4.0 International License (CC BY 4.0).
Rohan Deshmukh, Aarti Kulkarni (2026). Fatigue Life Prediction of 3D-Printed PLA Components Under Cyclic Loading. IJEIA, 1(3), 9-16.