Local stress in the vicinity of the propagating cleavage crack tip in ferritic steel
Local stress in the vicinity of the propagating cleavage crack tip in ferritic steel
复制标题
铁素体钢中扩展解理裂纹尖端附近的局部应力
DOI：
10.1016/j.matdes.2018.02.037
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发表时间：
2018
影响因子：
8.4
通讯作者：
S. Aihara
中科院分区：
文献类型：
--
作者：
F. Yanagimoto;K. Shibanuma;K. Suzuki;T. Matsumoto;S. Aihara
本研究的目的是评估在一个扩展的解理裂纹尖端附近的局部拉应力的基础上相结合的实验和有限元分析。以往的研究表明，局部拉应力是钢中解理裂纹扩展和止裂行为中最相关的因素。然而，没有明确的实验证据表明局部拉应力保持恒定。这是因为三维效应难以分析考虑，因此在局部拉应力的评估中被忽略。因此，侧槽试样，以消除三维效应，使之成为可能的裂纹扩展作为一个二维问题。在等温实验中测量裂纹速度以确定局部拉伸应力。局部拉伸应力进行了评估，有限元分析两个钢样品在多个温度和施加的应力水平。结果表明，每种钢的局部拉应力几乎是恒定的。因此，局部拉应力可以被认为是解理裂纹扩展中的相关材料阻力特性。这项研究得到了强有力的实验证据，局部断裂应力是非常适合用于描述解理裂纹扩展和制动行为的钢。
The objective of this research is to evaluate local tensile stresses in the vicinity of a propagating cleavage crack tip based on a combination of experiments and finite element analyses. Previous studies identified the local tensile stress as the most relevant factor in cleavage crack propagation and arrest behaviors in steels. However, there is no clear experimental evidence that the local tensile stress remains constant. This is because three dimensional effects are difficult to consider analytically and are thus ignored in the evaluation of local tensile stresses. Therefore, side-grooved specimens were employed to eliminate the three dimensional effect and make it possible to regard crack propagation as a two dimensional problem. Crack velocities were measured in isothermal experiments to determine local tensile stresses. Local tensile stresses were evaluated by finite element analyses for two steel samples at multiple temperatures and applied stress levels. The results show that the local tensile stresses were nearly constant for each steel. Thus, the local tensile stress can be considered the relevant material resistance property in cleavage crack propagation. This study yielded strong experimental evidence that the local fracture stress is well suited for use in describing cleavage crack propagation and arrest behavior in steels.