Evaluation of Early Fatigue Damage Detection in Additively Manufactured AlSi10Mg

The article presents two distinct measures for fatigue damage detection in additively manufactured AlSi10Mg specimens with a one-sided V-notch. The specimens are fabricated on a ProX-320 laser powder bed fusion equipment with recycled AlSi10Mg powders using vetted process parameters as suggested by 3D Systems. The process of fatigue damage evolution is monitored using two heterogeneous sensing techniques, namely, the force-displacement sensors and a confocal microscope. The force and displacement sensors are embedded in the fatigue testing apparatus to capture the global effects of the stress-strain behavior of the specimens; however, it provides no information about the local damage near the notch. The force-displacement time-series data, which shows a hysteresis-like behavior, is calibrated using a confocal microscope focused inside the notch of the specimen so that the onset of fatigue crack initiation can be detected at a crack opening displacement (COD) of ~10 microns. Using the force-displacement data, the energy dissipation rate and the material stiffness per cycle are computed. The results show a detection accuracy of 96.25% and 90.84% for the energy dissipation rate and material stiffness per cycle, respectively. In conclusion, the paper establishes two successful predictors for fatigue damage detection in additively manufactured AlSi10Mg specimens.Mechanical Engineerin