Numerical Simulation of Corrosion Attack on Al-Cu-Li 2198 Alloy in Different Ageing Tempers

A comprehensive experimental and numerical study was conducted on the effect of corrosion attack on the mechanical behaviour of AA2198 for two different ageing tempers, namely T3 and T8, respectively. The experimental investigation included pre-exposure to exfoliation corrosion environment, depth-of-attack measurements and finally tensile testing for different investigated corrosion exposure times. Corrosion attack was modelled, both as pitting distribution on the damaged surface and as pitting depth as surface notches of AA2198 and for different ageing tempers (T3 and T8) to investigate the effect of ageing on the corrosion-induced tensile properties degradation mechanism. A three-dimensional parametric finite element model was developed to take as an input the size and shape of the corrosion products using ANSYS software. The randomness of size and shape of corroded products was also considered. The evolution of damage during tensile loading is predicted using a progressive damage modelling scheme. The model can assess the residual tensile mechanical properties of corroded structures and provide useful information concerning the mechanics of damage evolution from the deteriorated surface.