Fatigue life prediction of the additively manufactured specimen

摘要

Additively manufactured specimens generally exhibit comparable or improved tensile properties, such as yield stress, ultimate tensile strength, and uniform elongation, compared to conventionally manufactured specimens. However, the defects that are typically present in additively manufactured microstructures result in inferior fatigue performance. A representative volume element-based modeling technique incorporating these defects has been used to predict the reduction in endurance limit of an additively manufactured stainless steel compared to the conventionally manufactured material. This physics-based model can clearly demonstrate the poor fatigue performance of additively manufactured specimens based on the micro-plasticity generated by the defects in the microstructure under cyclic loading. A Neuber analytical model has also been applied to predict the fatigue life of additively manufactured materials for a given stress amplitude. Both the prediction from the finite element model and the analytical Neuber model are very close to the experimental endurance limit.