Abstract:
Coarse-grained superalloys are critical for high-temperature applications like gas turbines, but their material behavior is not uniform at the microstructural level, especially near geometric features like notches. This study numerically investigates the resulting variation in fatigue behavior. A Monte Carlo analysis was conducted using 100 finite element (FE) simulations of a notched specimen, where the placement and orientation of each grain were randomized. Each grain was modeled as a unique, anisotropic single-crystal. The simulations revealed a considerable dispersion in predicted fatigue crack initiation life, demonstrating that the effect of the random grain structure is significant. The study concludes that a single, deterministic analysis based on a homogenized material is insufficient and that this inherent scatter must be accounted for in the life prediction of industrial components.
