On temperature scaling in dislocation mechanics
On temperature scaling in dislocation mechanics
复制标题
位错力学中的温标
DOI：
10.1016/j.jmps.2022.105102
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发表时间：
2022
影响因子：
5.3
通讯作者：
V. Berdichevsky
中科院分区：
文献类型：
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作者：
V. Berdichevsky
位错塑性的宏观理论必须尊重潜在位错动力学的标度性质。本文研究了含温度和Burgers矢量的位错动力学的标度性质。标度性质是在有限的动力学方程中建立的，推测它们在一般情况下应该成立。这一猜想得到了稳态应力和Voce应力实验数据的汇编的支持。为了描述新出现的尺度不变的实验相关性，提出了应力-应变率-温度本构关系的尺度不变形式。它还符合位错动力学的另一个特征，即当热涨落为零时，具有非平凡的刚性-粘性极限。本构方程对实验数据进行了合理的拟合。
Macroscopic theory of dislocation plasticity must respect the scaling properties of underlying dislocation dynamics. In this paper the scaling properties of dislocation dynamics involving temperature and Burgers vector are found. The scaling properties are established in a limited setting of dynamical equations, and it is conjectured that they should hold in general case. This conjecture is supported by a compilation of experimental data for steady state stresses and Voce stresses. In order to describe the emerging scale-invariant experimental dependencies, it is suggested a scale-invariant form of stress–strain rate–temperature constitutive relation. It also obeys to another feature of dislocation dynamics, a nontrivial rigid-viscous limit when thermal fluctuations go to zero. The constitutive equation yields a reasonable fit of experimental data.