Fatigue Life Prediction Based on Damage Line under Variable Amplitude Loads

A novel method based on damage line is put forward to improve the prediction accuracy of fatigue life under variable amplitude loads. According to fatigue strength change before and after the damage line, mechanical parts service processes are divided into undamaging and damaging process. Undamaging process life, damaging process life and fatigue life are calculated by the novel method. The prediction results are closer to the actual situation. In order to simplify calculation, the damaging process is regarded as linear process. The results are more accurate than traditional fatigue life prediction method. The novel method can be widely used in light-weight constructions, reduction of time-to-market period, product safety, reliability design and so on.