Simulating the fatigue crack in the PZL-130 TC-II aircraft structure

Within the following article authors present the methodology for estimating crack propagation within the PZL-130 TC-II trainer aircraft structure. The considered crack initiated in the starboard of the fuselage near the canopy lock mechanism mounting holes during the Full Scale Fatigue Test (FSFT) and was discovered during a Non Destructive Investigation (NDI). The main goal of the presented work was to determine the crack propagation curve taking into account the geometry of the damaged element as well as the adjacent structure, material properties and the actual load spectrum used during the FSFT. Obtained curve was used to estimate safe NDI intervals during operation. Authors present results only for the considered damage, however identical methodology was used for other nine Critical Points (CP) determined during the FSFT.