Pile-up/sink-in of rate-sensitive nanoindentation creeping solids
Pile-up/sink-in of rate-sensitive nanoindentation creeping solids
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DOI：
10.1088/0965-0393/15/7/008
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发表时间：
2007-10-01
影响因子：
1.8
通讯作者：
Elmustafa, A. A.
中科院分区：
文献类型：
--
作者：
Elmustafa, A. A.
堆积和下沉会影响压痕硬度测试中接触面积的测量，特别是当压痕尺寸变得非常小时，即在纳米压痕中。本文研究了应变速率和加工硬化对压痕过程中蠕变固体堆积和下陷的影响。我们使用的应变硬化蠕变本构关系，在ABAQUS有限元分析商业代码。模拟是针对加工硬化指数chi =偏导数ln sigma/偏导数ln sigma为0.1-0.3和冯米塞斯应力的应变速率敏感性v（sigma）=偏导数ln sigma/偏导数ln sigma为0.04-0.16进行的。我们报告的应变速率敏感性和加工硬化的影响措施的堆积和sink-ins. It是在文献中报道，率不敏感的材料进行下沉与加工硬化指数的增加，往往堆积在没有加工硬化。在对速率敏感材料的这项研究中，我们观察到类似的行为，但影响不那么深刻。我们也描绘了类似的结果堆积。
Pile-ups and sink-ins influence the measurement of the contact area in indentation hardness testing particularly when the indent size becomes significantly small, i.e. in nanoindentation. In this paper, we study the effect of strain rate and work hardening on pile-ups and sink-ins of creeping solids during the indentation process. We use a strain hardening creeping constitutive relation available in the ABAQUS finite element analysis commercial code. The simulations were performed for a work hardening exponent, chi = partial derivative ln sigma/partial derivative ln epsilon of 0.1-0.3 and a strain rate sensitivity of von Mises stress v(sigma) = partial derivative ln sigma/partial derivative ln epsilon of 0.04-0.16. We report that strain rate sensitivity and work hardening influence the measure of pile-ups and sink-ins. It is reported in the literature that rate-insensitive materials undergo sink-in with the increase in the work hardening exponent and tend to pile-up in the absence of work hardening. In this research for rate-sensitive materials, we observe similar behavior but the effect is less profound. We also depict similar results for pile-up.