Abstract: The anisotropic fatigue behavior of aircraft aluminum alloy plate was investigated by using bending fatigue test. The results show that after the rolling process, Al7475-T3 forms a pancake structure and the resistance to fatigue damage has been improved. The specimens taken from the 3 plans (S-T,S-L,T-L) show the highest fatigue strength reaches 200 MPa in the room temperature bending fatigue test, except the performance of plan T-L is isotropic, the other two plans S-T and S-L both show us anisotropic. Based on the weakest link theory, using the probabilistic fatigue criterion, the simulation of the anisotropic fatigue is applied to analyze the possibility of the nucleation of microcracks in the aluminum plate, but the result of the simulation is far from that of the actual situation. Taking into consideration of both the effective slip length of grains and the size of inclusions which affect the fatigue strength in the model, the Kitagawa curve is in good agreement with the actual situation.

Key words: fatigue, rolling, anisotropy, Al7475, simulation