Pitting Corrosion as a Failure Mechanism in Aircraft Panels: A Modelling and Simulation Approach

Pitting corrosion is a significant failure mechanism in aging aircraft structures, potentially leading to catastrophic structural failures. This study investigates the stress distribution around idealized cylindrical corrosion pits in aluminium aircraft panels under uniaxial tensile loading using three-dimensional finite element analysis (3D FEA). A systematic approach was employed to analyse the influence of varying pit diameters and depths on stress concentration. The maximum stress concentration was consistently observed at the pit’s anterior surface, perpendicular to the loading direction. A novel modified formula was developed to calculate the stress concentration factor (SCF) in pitted panels, considering the remaining material thickness, and providing a more accurate prediction compared to traditional methods. The results revealed a clear relationship between the pit aspect ratio (depth/diameter) and the SCF. A bi-linear material model was implemented to determine the yield strength of the panel under these conditions. The analysis also explored the stress concentrations associated with triangular pit geometries, demonstrating elevated stress levels compared to cylindrical pits of equivalent area. These findings offer critical insights into the structural integrity of aircraft panels affected by pitting corrosion. The proposed novel formula improves the prediction of structural failure and can be applied to enhance design and maintenance protocols in the aerospace industry to improve aircraft longevity and safety.