Fabric development with nearest‐neighbor interaction and dynamic recrystallization
Fabric development with nearest‐neighbor interaction and dynamic recrystallization
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利用最近邻相互作用和动态重结晶进行织物开发
DOI：
10.1029/2001jb000244
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发表时间：
2002
影响因子：
--
通讯作者：
T. Thorsteinsson
中科院分区：
文献类型：
--
作者：
T. Thorsteinsson
经过延性变形的多晶由于晶内滑移而形成晶格优先取向（织构）。织物发展的一个结果是，大块的物理性质变得各向异性。通过考察晶体间的最近邻相互作用（NNI）、多角化和迁移再结晶三种效应，研究了织物的发育和宏观变形。通过将晶体排列在三维立方网格上并为每个晶体分配六个相邻晶体来模拟NNI的影响。相互作用的“强度”可以从没有相互作用（均匀的应力）到“强”相互作用（显著的应力重新分配）不等。增加NNI会导致更均匀的应变。织物在一定体积应变下的强度和对称性都不同，这取决于NNI的强度。对于规定的织物，应变率随着NNI的增加而增加。再结晶是基于能量平衡的考虑，而多角化是根据应力差来表示的。这两个过程都需要了解位错密度，在模型中，位错密度是作为晶体应变和晶粒尺寸的函数来计算的，两者都随时间而变化。包含NNI的冰中织物发育模型比具有均匀应力的模型更真实。然而，现有的织物演变数据不足以定量地确定NNI在冰中的强度。
[1] Polycrystals undergoing ductile deformation develop lattice-preferred orientation (fabric) as a result of intracrystalline slip. A consequence of fabric development is that bulk physical properties become anisotropic. Fabric development and macroscopic deformation are studied by examining three effects: nearest-neighbor interaction (NNI) among crystals, polygonization, and migration recrystallization. The effects of NNI are modeled by arranging the crystals on a three-dimensional cubic grid and assigning six neighbors to each crystal. The “strength” of interaction can vary from no interaction (homogeneous stress) to “strong” interaction (significant stress redistribution). Increasing the NNI leads to a more homogeneous strain. Fabric varies in both strength and symmetry at a given bulk strain, depending on the strength of NNI. For a prescribed fabric the strain rate increases as the NNI increases. Recrystallization is modeled from energy balance considerations, and polygonization is formulated in terms of stress differences. Both processes require knowledge of dislocation density, which is calculated in the model as a function of crystal strain and grain size, both of which vary with time. Models of fabric development in ice that include NNI lead to more realistic fabric evolution than models with homogeneous stress. However, available data on fabric evolution are inadequate to determine quantitatively the strength of NNI acting in ice.