Theory of Critical Distances versus Gradient Mechanics in modelling the transition from the short to long crack regime at the fatigue limit
Theory of Critical Distances versus Gradient Mechanics in modelling the transition from the short to long crack regime at the fatigue limit
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临界距离理论与梯度力学在疲劳极限下从短裂纹状态到长裂纹状态的过渡建模
DOI：
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发表时间：
2013
期刊：
影响因子：
--
通讯作者：
D. Taylor
中科院分区：
文献类型：
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作者：
L. Susmel;H. Askes;T. Bennett;D. Taylor
检查的最新技术表明，在过去的三十年中，已经进行了大量的工作，以正式的具体方法，适用于准确地模拟从短到长的裂纹制度的过渡，临界距离理论（TCD）提供了一个合适的替代这些方法的基础上的线弹性断裂力学的概念。TCD假设疲劳裂纹的扩展发生在有效应力范围（取决于材料特征长度）超过材料平面疲劳极限时。采用类似的原理，梯度力学（GM）假设相关的线弹性应力场可以通过直接将材料长度尺度纳入应力分析本身来确定。GM最显著的特点是奇异应力场被平滑化。因此，即使本构关系是线弹性的，裂纹尖端应力也是有限值的。然后，在本调查中，建立一个明确的理论联系后，根据TCD和GM，分别计算的材料固有长度，它是通过大量的实验结果，从文献中，平滑的线弹性裂纹尖端应力是成功的模拟从短到长的裂纹区域的过渡。
Examination of the state of the art shows that over the last three decades, much work has been carried out to formalise specific methods suitable for accurately modelling the transition from the short to long crack regime, the Theory of Critical Distances (TCD) offering a suitable alternative to those methods based on the linear elastic fracture mechanics concepts. The TCD takes as a starting point the assumption that the propagation of fatigue cracks occurs when an effective stress range, depending on a material characteristic length, exceeds the material plain fatigue limit. Adopting a similar philosophy, gradient mechanics (GM) postulates that the relevant linear elastic stress fields can be determined by directly incorporating the material length scale into the stress analysis itself. The most remarkable feature of GM is that singular stress fields are smoothened. Thus, a finite value of the crack tip stress is obtained even if the constitutive law is linear elastic. In the present investigation then, after establishing an explicit theoretical link between the material intrinsic lengths calculated according to the TCD and GM, respectively, it is shown, through numerous experimental results taken from the literature, that the smoothened linear elastic crack tip stresses are successful in modelling the transition from the short to long crack region.
影响因子：
4.1
作者：
T. Bennett;H. Askes
通讯作者：
T. Bennett;H. Askes
DOI：
10.1016/j.ijsolstr.2011.03.006
发表时间：
2011-06-15
影响因子：
3.6
作者：
Askes, Harm;Aifantis, Elias C.
通讯作者：
Aifantis, Elias C.