Reconsiderations of fatigue crack growth at negative stress ratios: Finite element analyses
Reconsiderations of fatigue crack growth at negative stress ratios: Finite element analyses
复制标题
DOI：
10.1016/j.engfracmech.2015.07.022
复制
发表时间：
2015-08
影响因子：
5.4
通讯作者：
C. Benz;M. Sander
中科院分区：
文献类型：
--
作者：
C. Benz;M. Sander
在这项研究中，重新考虑了负应力比下疲劳裂纹扩展的两个重要方面。首先，讨论了控制裂纹尖端加载参数的方法。已有研究表明，K(Kmax orΔK)和Re不适合描述负裂纹部分的裂纹尖端载荷。结果表明，在负载荷作用下，另一个基于应力的参数与裂纹尖端载荷相关。其次，对负应力比下的变形机理进行了深入探讨。因此，提出了一种新的方法来可视化裂纹尖端前后，甚至是负载荷部分的塑性变形。研究了恒幅和变幅加载现象。
Two important aspects of fatigue crack growth at negative stress ratios are reconsidered within this study. First, the controlling crack tip loading parameters are discussed. As already shown in former studiesK(Kmaxor ΔK) andRare not suitable to describe properly the crack tip loading for the negative part. It is proven that an alternative stress based parameter correlates with the crack tip loading for negative loads. Second, the deformation mechanisms at negative stress ratios are intensively discussed. Therefore a new method is proposed in order to visualize the plastic deformations before and behind the crack tip, even at the negative loading part. Phenomena of constant and variable amplitude loading are investigated.