LAUSR

Abstract Defect tolerant design has played a significant role in the aerospace industry for qualifying new materials and retiring legacy components. One tool used in this design framework, the El-Haddad model, demonstrates how fatigue limit stress changes with respect to the size of a material defect. This paper enhances the legacy model to include finite life behavior and stress ratio effects. This enhancement is vetted against literature data from numerous sources, and it is shown quantitatively that the improved model accurately approximates crack growth rate behavior and represents in(finite) fatigue life of experimental components across multiple load ratios and defect sizes.