Evaluation of Threshold Condition of Interior Annular Crack Growth in Gigacycle Regime

摘要

Gigacycle fatigue properties with interior-induced failure of three high strength steels under different loading conditions were investigated, and an experimental-theoretical method is proposed to quantitatively evaluate the threshold condition of interior crack growth. The entire growth process consists of small crack growth within fine granular area (FGA), stable long crack growth outside of FGA within fish-eye and unstable crack growth outside of fish-eye. Based on the comparison between evaluated and experimental results, the validity of method is verified.