Simple shear simulation of 3D irregularly-shaped particles by image-based DEM
Simple shear simulation of 3D irregularly-shaped particles by image-based DEM
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DOI：
10.1007/s10035-010-0207-6
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发表时间：
2010-10-01
期刊：
影响因子：
2.4
通讯作者：
Yamada, Yasuo
中科院分区：
文献类型：
--
作者：
Katagiri, Jun;Matsushima, Takashi;Yamada, Yasuo
本文描述了一种基于图像的DEM，它直接考虑了固体颗粒的不规则形状。为了获得高质量的CT图像，正确地检测颗粒的形状，使用了SPEMP-8(日本的同步辐射装置)的微型X射线CT。通过原始的图像处理技术自动获得每个颗粒的数字化三维形状数据。采用动态优化方法，用多个球面单元簇来模拟颗粒形状。建模的精度可以由组成每个粒子的元素的数量来控制。利用这种模拟颗粒，对不同孔隙率的试件进行了一系列简单剪切模拟。结果表明，10单元模型可以定量地再现相对致密试件的剪切行为。另一方面，为了更好地模拟松散试件的堆积结构和剪切行为，10单元模型是不够的，需要更精确的模型。这一结果表明，与颗粒间传递力矩有关的整体颗粒形状在密集堆积的颗粒组装中是重要的，而小表面角度在松散堆积的颗粒组装中起着相当大的作用。
This paper describes an image-based DEM taking account of the irregular shape of solid particles in a direct manner. A micro X-Ray CT at SPring-8 (a synchrotron radiation facility in Japan) was employed to obtain high quality CT images for detecting correctly the shape of particles. The digitized 3D shape data of each particle was automatically obtained by an original image-processing technique. The particle shape was modeled by a cluster of several spherical elements using dynamic optimization method. The accuracy of the modeling can be controlled by the number of elements forming each particle. Using such modeled particles a series of simple shear simulations were performed for the specimens with various void ratios. It was found that 10-element model can quantitatively reproduce the shear behavior of relatively-dense specimens. On the other hand, in order to well simulate the packing structure and the shear behavior of loose specimens, 10-element model is found to be insufficient and more accurate model would be necessary. This result implies that the overall grain shape that is relevant to the moment transmission between grains is important in densely-packed granular assembly, while small surface angularity plays considerable role in loosely-packed granular assembly.