Multi-scale parallel finite element analyses of LDH sheet formability tests based on crystallographic homogenization method
Multi-scale parallel finite element analyses of LDH sheet formability tests based on crystallographic homogenization method
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DOI：
10.1016/j.ijmecsci.2009.09.007
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发表时间：
2010-02
影响因子：
7.3
通讯作者：
H. Kuramae;Y. Ikeya;H. Sakamoto;H. Morimoto;E. Nakamachi
中科院分区：
文献类型：
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作者：
H. Kuramae;Y. Ikeya;H. Sakamoto;H. Morimoto;E. Nakamachi
将基于晶体学均匀化方法的多尺度并行有限元程序应用于LDH板材成形性试验分析。对于多尺度结构，考虑两个尺度。一个是微观多晶结构，另一个是宏观弹塑性连续体。分析代码可以预测宏观尺度的金属板的可成形性，同时预测微观尺度的晶体织构和硬化演变（Nakamachi E等人，Int J Plasticity 2007;23：450-8）。由于非线性动态多尺度FE分析需要大量的计算时间，因此使用消息传递接口（MPI）库和PC集群将基于宏连续体的FE模型的域划分的并行计算技术引入到多尺度代码中（Kuramae H等人，在：Proceedings of the eighth International Conference on Computational Plasticity，Part 1，2005中）。第622-5页）。非线性多尺度有限元动力学问题的显式时间步进求解方法不需要求解联立方程，非常适合在PC机群等分布式存储环境下进行并行计算。利用扫描电子显微镜（SEM）和电子背散射衍射（EBSD）分析技术，对A6022-T43和A5182-O、A6022-ASR和HC 220 YD四种汽车板材的晶体形貌进行了测量，定义了微观多晶结构的三维代表体积元（RVE），满足晶体取向分布的周期性条件。通过多尺度LDH试验分析，我们不仅评估了汽车板料的宏观成形性，而且还评估了塑性变形过程中微晶织构的演变。此外，宏观成形性和微晶织构演变之间的关系进行了讨论，通过查看多尺度有限元结果。结果表明，HC 220 YD低碳钢在塑性变形过程中，由于保留并产生了{111}<$110 <$-{111}<$112 <$取向的γ纤维织构，其成形性能优于铝合金板材。
A multi-scale parallel finite element (FE) procedure based on the crystallographic homogenization method was applied to the LDH sheet formability test analysis. For the multi-scale structure, two scales are considered. One is a microscopic polycrystal structure and the other is a macroscopic elastic plastic continuum. The analysis code can predict the formability of sheet metal in macro-scale, simultaneously the crystal texture and hardening evolutions in the micro-scale (Nakamachi E et al. Int J Plasticity 2007;23:450–8). Since huge computation time is required for the nonlinear dynamic multi-scale FE analysis, parallel computing technique based on domain partitioning of FE model for macro-continuum is introduced into the multi-scale code using the message passing interface (MPI) library and PC cluster (Kuramae H et al. In: Proceedings of the eighth international conference on computational plasticity, Part 1, 2005. p. 622–5). The explicit time stepping solution scheme in the nonlinear multi-scale FE dynamic problem is well-suited for parallel computing on distributed memory environment such as PC cluster because solving simultaneous equation is not required. We measured crystal morphologies of four automotive sheet metals, aluminum alloy sheet metals A6022-T43 and A5182-O, an asymmetrically rolled aluminum alloy sheet metal A6022-ASR, and mild steel HC220YD, by using the scanning electron microscope (SEM) with electron back scattered diffraction (EBSD) analyses, and defined a three-dimensional representative volume element (RVE) of micro polycrystal structure, which satisfy the periodicity condition of crystal orientation distribution. We evaluate not only macroscopic formability of the automotive sheet metals by the multi-scale LDH test analysis, but also microcrystalline texture evolution during plastic deformation. Furthermore, a relationship between the macroscopic formability and the microcrystal texture evolution was discussed through looking at multi-scale FE results. It is concluded that the mild steel HC220YD was the highest formability than the aluminum alloy sheet metals because of remaining and generating the γ-fiber texture, such as {111}〈110〉–{111}〈112〉 orientations, during plastic deformation.