Assessment of the Effect of Multiscale Geometrical Discontinuities on Fatigue Performance of Additively Manufactured Ti6Al4V

ABSTRACT For additively manufactured (AM) components, the quantitative effects of different scale geometrical discontinuities on fatigue performance have not been fully understood. This paper systematically investigates the different scale geometrical discontinuities present in AM Ti6Al4V and proposes a unified life prediction method to take these geometrical discontinuities into account. The effect of pores on fatigue performance is uncoupled from the microstructure. The Chaboche cyclic elasto‐plastic constitutive model with a mixed non‐linear hardening rule has been modified for a better description of the AM Ti6Al4V. Fatigue lives are predicted using local stress and strain computed by FEM, and a Smith–Watson–Topper (SWT)‐based life prediction method is proposed while considering the effects of as‐built surfaces, micro‐scale notches, and macro‐scale notches. The proposed fatigue life prediction method is validated using massive fatigue data.