Fatigue Life Prediction of Additive Manufactured Materials Using a Defect Sensitive Model

Muhammad, Muztahid
Carrion, Patricio E.
Shamsaei, Nima
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University of Texas at Austin

This study utilized a defect sensitive fatigue model based on a fracture mechanics concept to predict the fatigue life of 17-4 precipitation hardening (PH) stainless steel (SS) fabricated using laser beam powder bed fusion (LB-PBF) process. Size of defects such as gas entrapped pores are captured using fractography analysis and calculated employing Murakami’s approach with the √area method. Considering the value of the √area as initial crack length, fatigue life is then calculated using NASGRO software, and compared to the experimental data obtained from strain-controlled fatigue testing. A comparison between predicted fatigue lives using NASGRO software, combined with the Murakami approach, and experimentally obtained ones were presented to determine the applicability of the utilized model for predicting the fatigue performance of additive manufactured materials.