PREDICTION OF FATIGUE-CRACK RATE IN AL-7010 ALLOY WITH FIBROUS AND RECRYSTALLIZED STRUCTURE

FEM elastic-plastic simulations of the fatigue crack growth in CT spec imens made of Al 7010 alloy with fibrous and recrystallized structure under constant amplitude loading with the stress ratio R = 0.7 and R = 0 were performed. A comparison of theoretical and experimental result s shows that the rate of fatigue crack growth in thin walled bodies ma de of this alloy can quite well be predicted from low-cycle fatigue of the material at the crack tip under plane stress conditions. However, the crack-tip cyclic plasticity under plane strain conditions is not very intensive and does not correspond with the high crack rate in the thick wall.