Accounting for anisotropic, anisothermal, and inelastic effects in crack initiation lifing of additively manufactured components.

The crack initiation life of a ductile additively manufactured nickel‐based superalloy is studied and modeled for low‐cycle fatigue and thermomechanical fatigue conditions up to 600°C. Isothermal experiments were performed on smooth specimens at temperatures up to 600°C with different applied strain ranges. Additionally, thermomechanical fatigue experiments at 100–450°C and 100–600°C were performed on smooth specimens under in‐phase and out‐of‐phase conditions. A life prediction model accounting for the anisotropy was developed, where the temperature cycle is accounted with a ΔT‐functionality, generating good agreements with the experiments. The model was also validated on notched specimens undergoing thermomechanical fatigue conditions at 100–500°C using simplified notch correction methods. Highlights: The fatigue crack initiation life of an additive manufacturing (AM) combustor alloy was studied.Isothermal and anisothermal conditions up to 600°C were studied.The life prediction model accounts for the anisotropic behavior.Dependence of Tmax and ΔT was used for the life prediction constants.The model predicts the experimental life with good agreement. [ABSTRACT FROM AUTHOR]