Numerical microstructure model of NiTi wire reconstructed from 3D-XRD data
Numerical microstructure model of NiTi wire reconstructed from 3D-XRD data
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DOI：
10.1088/1361-651x/ab89c1
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发表时间：
2020-05
影响因子：
1.8
通讯作者：
L. Heller;I. Karafítov́;L. Petrich;Z. Pawlas;P. Shayanfard;V. Beneš;V. Schmidt;P. Šittner
中科院分区：
文献类型：
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作者：
L. Heller;I. Karafítov́;L. Petrich;Z. Pawlas;P. Shayanfard;V. Beneš;V. Schmidt;P. Šittner
本文利用3D-XRD数据重建了多晶NiTi线材在拉伸载荷作用下的晶粒微观结构和应变分配。包含8000多个应力颗粒的体积的重建涉及相对于几何特征和材料弹性性质的优化。基于实验3D-XRD数据集，使用Laguerre棋盘格重构微观结构的几何特征。应用了两种不同的拉盖尔曲面细分拟合算法，以评估重建对算法选择的敏感性。根据弹性各向异性的材料特性从初始公布的值进行了改进，以使用基于线性弹性模拟的优化算法来最小化实验与模拟之间的失配。因此，我们构建了一个数值微观结构模型，该模型在统计学上与实验探测的材料在晶粒的位置和尺寸以及微观结构中弹性应变和应力的划分（平均弹性特性和晶粒中弹性应变和应力张量的分段常数分量的标准偏差）方面相匹配。
In this paper, the grain microstructure and strain partitioning in a polycrystalline NiTi wire subjected to tensile loading was reconstructed from an experimental 3D-XRD dataset. The reconstruction of a volume containing more than 8000 stressed grains involved optimization with respect to both the geometrical features and material elastic properties. The geometrical features of the microstructure were reconstructed using Laguerre tessellations based on the experimental 3D-XRD dataset. Two different algorithms fitting Laguerre tessellations were applied in order to assess the sensitivity of the reconstruction to the choice of the algorithm. The material properties in terms of elastic anisotropy were refined from an initial published value to minimize the mismatch between experiment and simulation using an optimization algorithm based on linear elasticity simulations. As a result of this, we constructed a numerical microstructure model that statistically matches the experimentally probed material in terms of positions and sizes of grains as well as partitioning of elastic strain and stress in the microstructure (average elastic properties and standard deviations of piecewise constant components of elastic strain and stress tensors in grains).