Compact reconstruction of orientation distributions using generalized spherical harmonics to advance large-scale crystal plasticity modeling: Verification using cubic, hexagonal, and orthorhombic polycrystals
Compact reconstruction of orientation distributions using generalized spherical harmonics to advance large-scale crystal plasticity modeling: Verification using cubic, hexagonal, and orthorhombic polycrystals
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DOI：
10.1016/j.actamat.2018.06.017
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发表时间：
2018-08-15
期刊：
影响因子：
9.4
通讯作者：
Knezevic, Marko
中科院分区：
文献类型：
--
作者：
Eghtesad, Adnan;Barrett, Timothy J.;Knezevic, Marko
在晶体塑性模拟中，晶体织构数据的压缩是非常需要的，因为此类计算中涉及的计算时间与晶体取向的数量成线性比例。在最近的出版物中，我们报告了使用对称广义球谐函数（GSH）函数减少立方正交各向异性和六方正交各向异性多晶金属晶体取向的大型数据集的严格程序。该过程依赖于使用取向分布函数 (ODF) 的晶体织构的定量描述及其使用 GSH 的级数表示。核心程序包括将包含任意数量晶体取向的全尺寸 ODF 的光谱表示与包含一组紧凑取向的 ODF 的光谱表示进行匹配。在本文中，我们将该过程推广到任何晶体结构，对样品对称性没有限制。这些主要扩展伴随着处理更多的维度和虚数项。探索了在紧凑 ODF 中生成初始方向集的两种方法，一种基于 Bunge-Euler 方向空间中给定基本区域的分箱，另一种利用 MTEX 来最大化压缩。整个过程已成功应用于压缩具有正交各向异性且无样品对称性的立方、六方和斜方多晶金属的大型 ODF。定量证明，使用晶体塑性有限元模型，可以通过紧凑的 ODF 精确模拟样品的织构演化、孪晶体积分数演化、应力应变响应和几何变化。 (C) 2018 Acta Materialia Inc. 由 Elsevier Ltd 出版。保留所有权利。
Compaction of crystallographic texture data is highly desirable in crystal plasticity simulations because the computational time involved in such calculations scales linearly with the number of crystal orientations. In a recent publication, we have reported a rigorous procedure for reducing large datasets of crystal orientations for cubic-orthotropic and hexagonal-orthotropic polycrystalline metals using symmetrized generalized spherical harmonics (GSH) functions. The procedure relies on a quantitative description of crystallographic texture using an orientation distribution function (ODF) and its series representation using GSH. The core procedure consists of matching the spectral representation of a fullsize ODF containing any number of crystal orientations with that of an ODF containing a compact set of orientations. In this paper, we generalize the procedure to any crystal structure with no restrictions to sample symmetry. These major extensions are accompanied by dealing with significantly more dimensions as well as imaginary terms. Two approaches for generating an initial set of orientations in the compact ODF are explored, one based on binning of a given fundamental zone in the Bunge-Euler orientation space and another that takes advantage of MTEX to maximize the compaction. The overall procedure has been successfully applied to compaction of large ODFs for cubic, hexagonal, and orthorhombic polycrystalline metals with orthotropic and no sample symmetry. It is quantitatively demonstrated that texture evolution, twin volume fraction evolution, stress-strain response, and geometrical changes of samples can be accurately simulated to large plastic strains with compact ODFs using crystal plasticity finite element models. (C) 2018 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.