基于损伤力学阐释Manson-Coffin低周疲劳模型

摘要

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.%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.