Fig. 4: Crack tip stress characteristics upon loading.

The crack opening stresses (COS), growth direction stresses (GDS) and σ_xx are shown for LS1, LS2, and LS3 in (a–c), respectively. The PST value introduced in Eq. 2 to verify the evaluated crack tip stresses is presented in (d–f), respectively, where the black contour line marks PST = 0.5, which can be attributed to full plastic deformation. Additionally, circles with a diameter of 5 µm in front of the crack tip represent the area from which values were taken for the statistical analysis shown in (g–i). Additionally, Poisson’s ratio υ_exp = 0.253 ± 0.017²⁴ for this HEA is indicated in (g). Finally, in (j–l) the triaxiality ratio, being the relation between the hydrostatic portion of the stress tensor and the von-Mises stress representing the strain energy of distortion, is shown. The black contour line in (j–l) corresponds to \(T=1/\sqrt{3}\approx 0.577\), representing a plane strain state. The error bars in (a–c) depict the standard deviation of the stress results.