Evaluation of Mean Stress Correction Approaches in High Cycle Fatigue Life Prediction of Titanium Alloy Considering Notch

The effect of notches & mean stress in fatigue of materials has been a subject of wider interest. The current study is focused on alpha-beta Titanium alloy (Ti-6Al-4V) which is a common material in aerospace applications. Various mean stress correction approaches are evaluated for notched & un-notched specimens.

Life predictions are obtained for a standard test specimen. For the zero mean condition, most approaches predict similar life. However for non-zero mean conditions, significant deviation is observed in life predictions for Titanium alloy (Ti-6Al-4V). Walker mean stress correction approach was found to be in close agreement with published test data. Walker constant is a significant parameter which influences life prediction accuracy. Study has been carried out to find suitable values of constant for different standard shapes/forms of raw material used for manufacturing.