A RV APPROACH FOR THE ANALYSIS OF FATIGUE CRACK GROWTH WITH NASGRO EQUATION

Inspection intervals of critical safety components should be calculated on the basis of sophisticated crack growth algorithms able to describe crack propagation under service loads. Although many probabilistic models exist in literature, generally speaking, crack growth equations (linear, bi-linear) are too simplistic for real FCG calculations of mechanical components, most of whose live are spent in the near-threshold regime. This paper deals with the analysis of a probabilistic description of crack growth based on the so-called ‘NASGRO propagation equation’. First and foremost, it addresses a description of Virkler’s crack growth data, which shows a significant correlation between the parameters m, logC and ΔKth. The analysis is then applied to a set of crack growth data obtained from a steel applied in the manufacturing of railway axles.