This study presents a detailed analysis of a fatigue test campaign in order to identify
different crack patterns. It was conducted on 6061-T6 aluminum tubular specimens featuring an
internal diameter of 10mmand different thicknesses (2, 3 and 4 mm). These specimens were subjected
to cyclic tensile loads with a load ratio of R = 0.1, utilizing a sinusoidal load function at a frequency
of 3 Hz. The investigation examines the crack growth rates, the stress intensity factor, and the
final and intermediate fracture zones by applying overloads in some cases. The differences with
two-dimensional specimens and the importance of this study for the interpretation of results with
biaxial loading states are highlighted. The different states of crack growth detected are analyzed using
artificial vision techniques. The differences between the exterior and interior faces of the specimen
are revealed, and a series of states prior to the formation of the radial crack front expected in these
specimens are identified.
