FINITE ELEMENT MODELLING IN PREDICTING THE EFFECT OF DEFECTS ON STRESS CONCENTRATION AND FATIGUE LIFE OF L-PBF ALSI10MG ALLOY

The elastic-plastic finite element analysis is performed to obtain the stress field around pores and evaluate their resultant effects on fatigue life for L-PBF (Laser Powder Bed Fusion) produced AlSi10Mg alloy. The stress field is calculated for both single and multiple pore models, where stress concentration is evaluated as a function of the pore location and its size. A multi-scale finite element (FE) model is proposed based on the inherent porosity data from Computed Tomography (CT) to predict the overall fatigue life with high (90%) accuracy. The predicted fatigue life (cycles) are calculated using the rainflow counting algorithm in fe-Safe software using the stress-strain data obtained from the proposed FE model developed using the Abaqus software. Using the proposed model, it is possible to generate S-N curves for any loading condition for a given porosity characteristic (porosity density and average pore size).
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