Abstract:Based on simulation accelerated pitting corrosion test results of 7B04 aluminum alloy specimen, which combined with the pitting corrosion mechanization and microstructure of aluminum alloy and stochastic process essence of pitting corrosion, two typical damage models with complex morphology which were composed of many micro-ellipsoid corrosion pits were erected through finite element method, two models were named wedging model and encircling model respectively. The stress concentration effect which was embodied by stress concentration factor and stress nephogram was calculated and analyzed through ANSYS software and linear elastic fracture mechanics. The results show that the stress concentration effect of wedging model and encircling model is very different from the results of simplified ellipsoid corrosion pits model. The stress concentration factor value of wedging model and encircling model is almost the same, and may increase because of interference and influence and superposition of each single micro-ellipsoid corrosion pits. The obvious area or location of stress concentration effect of wedging model and encircling model almost locates at the intersection region between each micro-ellipsoidal corrosion pit, the intersection regions almost are on the side of the macro corrosion pits. The size range of wedging model and encircling model stress concentration effect are well matched with the microscopic grain size and small crack size of aluminum alloy.