Figure 3. The shape of circular section defect. With (a) is a crack length, R is the section radius and 𝜎 is a tensile load

From

Determination of the Stress Intensity Factor with an Empirical Approach for Circular and Elliptical Cracked Sections

Hicham Laribou, Chadia Qotni

American Journal of Mechanical Engineering. 2022, 10(1), 9-16 doi:10.12691/ajme-10-1-2