Ensemble averaging stress–strain fields in polycrystalline aggregates with a constrained surface microstructure – Part 1: anisotropic elastic behaviour
Ensemble averaging stress–strain fields in polycrystalline aggregates with a constrained surface microstructure – Part 1: anisotropic elastic behaviour
复制标题
具有约束表面微观结构的多晶聚集体中的整体平均应力-应变场 - 第 1 部分：各向异性弹性行为
DOI：
10.1080/14786430601009509
复制
发表时间：
2007
影响因子：
1.6
通讯作者：
O. Bouaziz
中科院分区：
文献类型：
--
作者：
A. Zeghadi;F. N’guyen;S. Forest;A. Gourgues;O. Bouaziz
采用大尺度有限元和统计方法研究了三维晶粒形态对多晶聚集体自由表面变形的影响。基于原始的三维图像分析程序，在给定的二维表面z = 0处，包含39个具有给定晶体取向的晶粒，构建了17个随机的三维多晶聚集体，除了z = 0处，它们具有不同的三维晶粒形状和取向。它们受到全面拉伸载荷条件的影响。分析了自由表面z = 0处的应力-应变场。计算了观测地表应力场的集合平均图和方差图。在晶粒的各向异性弹性行为的情况下，在观察表面的给定材料点上，从微观结构的一种实现到另一种实现的等效应力水平的波动范围在5%至60%之间。这些结果对于比较金属多晶的有限元模拟和表面应变场测量具有重要意义。
The effect of three-dimensional (3D) grain morphology on the deformation at a free surface in polycrystalline aggregates is investigated by means of a large-scale finite element and statistical approach. For a given two-dimensional surface at z = 0 containing 39 grains with given crystal orientations, 17 random 3D polycrystalline aggregates are constructed having different 3D grain shapes and orientations except at z = 0, based on an original 3D image analysis procedure. They are subjected to overall tensile loading conditions. The resulting stress–strain fields at the free surface z = 0 are analyzed. Ensemble average and variance maps of the stress field at the observed surface are computed. In the case of an anisotropic elastic behaviour of the grains, fluctuations ranging between 5% and 60% are found in the equivalent stress level at a given material point of the observed surface from one realization of the microstructure to another. These results have important implications in the way of comparing finite element simulations and surface strain field measurements in metal polycrystals.