A unified expression for low cycle fatigue and extremely low cycle fatigue and its implication for monotonic loading
A unified expression for low cycle fatigue and extremely low cycle fatigue and its implication for monotonic loading
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DOI：
10.1016/j.ijfatigue.2008.03.004
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发表时间：
2008-10-01
影响因子：
6
通讯作者：
Xue, Liang
中科院分区：
文献类型：
--
作者：
Xue, Liang
众所周知，在极低周疲劳条件下，经验曼森-柯芬定律往往会过度预测循环寿命。本文提出了一种新的统一表达式来克服这一缺点。通过引入指数函数，这种新的表达式能够捕获极低周疲劳到低周疲劳的整个周期内的循环寿命，并提供额外的材料参数进行校准。现有文献中的实验数据用于证明所提出的表达式对几种多晶金属的适用性。讨论了新表达式对单调塑性断裂的意义。统一表达式中的指数对温度敏感。给出了热对材料常数影响的实例。(C) 2008 Elsevier Ltd版权所有。
it is well-known that the empirical Manson-Coffin law tends to over-predict the cyclic life under extremely low cycle fatigue condition. In the present paper, a new unified expression is proposed to overcome this shortcoming. By introducing an exponential function, this new expression is capable of capturing the cyclic life over the entire span of extremely low cycle fatigue to low cycle fatigue with an additional material parameter to calibrate. Experimental data from existing literature are used to demonstrate the applicability of the proposed expression for several polycrystalline metals. The implication of the new expression to monotonic plastic fracture is discussed. It is also identified that the exponent in the unified expression is sensitive to temperature. Examples are given for the thermal influence on the material constants. (C) 2008 Elsevier Ltd. All rights reserved.