Limit load of notched Ti-6Al-4V specimens under axial fatigue

Abstract

Ti-6Al-4V is used to manufacture aircraft components, that are subjected to fatigue loads during their service life. These components exhibit flaws and are susceptible to impact damage. Therefore, it is important to study the fatigue behaviour of Ti-6Al-4V in the presence of defects to accurately evaluate the fatigue life of components. This paper reports the limit load of notched Ti-6Al-4V specimens not subjected to solution treatment and over-aging under axial fatigue. The tests are carried out in inert environments using a step loading procedure, with a load ratio R = 0. The limit loads of the specimens with a notch depth / width of the specimens’ gauge section ratio d / D = 0.0439 and d / D = 0.0877 are similar and higher than the limit load of the specimen with d / D = 0.1754 since the net area at the minimum cross section of the third specimen is much smaller than the areas of the other two specimens. The nominal stress at failure referred to the net area is similar for the fatigued specimens.