关键词: 损伤演化规律, 非均匀损伤模型, 损伤等效法则, 交互影响因子, 疲劳寿命预测

Abstract:  In order to study the evolution law of fatigue damage of metal components， a non-uniform damage accumulation model and life prediction theory were established considering the interaction of loads. First， a non-uniform fatigue damage model was proposed based on residual life under constant amplitude loading. Secondly， the loading sequence effect was expounded， and it was proved that the proposed load loading sequence effect might be considered in the non-uniform damage model. Then， the interaction among loads was verified， and it was proposed that there was mutual influence between adjacent two-level loads， the load interaction factor was defined and introduced， and a new equivalent damage model was established. Finally， combining the non-uniform damage model with the new equivalent damage model， a non-uniform damage model was constructed under multi-level variable amplitude loads. Life prediction was carried out with the test data of 30NiCrMoV12 steel and Al-2024-T45 alloy under two-level loading. By comparing with various models， it was verified that the proposed model may predict fatigue life well. The proposed model has a certain reference value for the damage evolution law of metals. 

Key words: law of damage evolution, non-uniform damage model, law of damage equivalence, interaction impact factor, fatigue life prediction