Manson-Coffin model of low cycle fatigue is a classical empirical formula, and its mechanical implications are very pool. Based on damage mechanics and Ramberg-Osgood rule, a damage mechanics model of low cycle fatigue was deduced under the dominate variable of plastic strain amplitude. By the comparison with Manson-Coffin model, it is shown that they are equivalent under proportional loading and Manson-Coffin model is a special degenerative form of damage mechanics fatigue model.

low cycle fatigue, damage mechanics, equivalence;proportional loading

为验证Manson-Coffin低周疲劳模型经验公式，采用损伤力学基础理论，并结合Ramberg-Osgood幂率强化准则，以塑性应变幅值为损伤演化的控制量，推导建立了低周疲劳损伤力学模型。比较两者后可得：在比例载荷的条件下，

Manson-Coffin低周疲劳模型与疲劳损伤力学模型是等价的，且Manson-Coffin公式是疲劳损伤力学模型的一种特殊的退化形式。

低周疲劳, 损伤力学, 等价, 比例载荷