Creep-Fatigue Damage Analysis of TA12 Titanium Alloy Notched Sample at Elastic Stress Cycle with Dwell Time

Stress-strain under different creep-fatigue loads of double edge notched sample of TA12 titanium alloy with only elastic response at cyclic loading and unloading process was analyzed by finite element method. The creep fatigue life under different loads conditions were estimated by time-cyclic fraction method, and the fatigue damage and creep damage under correspondant conditions were analyzed. The results show that the contribution of creep damage and fatigue damage to creep fatigue damage of notched sample depended on the amplitude of the peak loads and the holding time of peak load. When the peak load was low and the notched sample was in elastic state, the creep damage had a considerable effect to creep-fatigue life. When the holding time was same, the fatigue damage increased gradually with the increase of peak loading and when the holding time reached a period of time, the effect of creep damage would exceed that of fatigue damage.