Recent studies have allowed us to identify a narrow region of the thickness of the crack
front in fracture problems that presents interesting characteristics for the numerical-experimental
correlation. Taking the three-dimensional distribution of the stress intensity factor (K) as a
reference, we observe how it remains invariant and independent of the main factors influencing this
type of analysis. This article presents a summary of how to identify this point through the numerical
simulation of the problem and its relationship with parameters such as thickness, load level or angle
of curvature. The simulations are carried out with the ANSYS software in an aluminium CT
specimen subjected to a fracture loading process in mode I.