Modelling of fatigue thresholds for small cracks in a mild steel by "Strip-Yield" model
Modelling of fatigue thresholds for small cracks in a mild steel by "Strip-Yield" model
复制标题
DOI：
10.1016/j.engfracmech.2009.04.015
复制
发表时间：
2009-07-01
影响因子：
5.4
通讯作者：
Madia, M.
中科院分区：
文献类型：
--
作者：
Beretta, S.;Carboni, M.;Madia, M.
机械构件的疲劳可以用非常小的疲劳裂纹的生长来解释，这些裂纹导致构件的最终断裂。因此，必须设法描述小裂纹的增长和阈值。本文采用条带屈服模型分析了一种广泛应用于铁路车轴制造的低碳钢的疲劳门槛值。此外，需要一个精确的定义的约束因子，根据循环，非线性响应的材料，解决，连同选择一个适当的约束制定。这导致在R =-1的长裂纹（从SE（B）标本）的疲劳门槛值预测良好，而北川图的描述（通过对人工缺陷的标本进行疲劳试验获得）是相对较差的小裂纹前的循环应力的分析，使我们能够比较的结果与McEvily，Usami和石田的小裂纹的门槛值模型。(C)2009爱思唯尔有限公司保留所有权利。
The fatigue of mechanical components can be explained by the growth of very small fatigue cracks, which lead to the final fracture of the component. It is, therefore, essential to try to describe the growth and the thresholds of small cracks. In this paper, the Strip-Yield model is used to analyse the fatigue thresholds of a mild-steel widely used for manufacturing railway axles. Furthermore, the need for a precise definition of the constraint factor, under cyclic, non-linear response of the material, is addressed, together with the choice of an appropriate constraint formulation. This results in good fatigue threshold predictions at R = - 1 for long cracks (obtained from SE(B) specimens), whereas the description of the Kitagawa diagram (obtained by fatigue tests on specimens with artificial defects) is relatively poor.The analysis of the cyclic stress ahead of small cracks enables us to compare the results with the threshold models for small cracks by McEvily, Usami and Shida. (C) 2009 Elsevier Ltd. All rights reserved.