Abstract This paper presents a numerical study on the packing structure of ellipsoidal particles under one-dimensional vibration and periodic boundary conditions by discrete element method. It is shown that after vibration, packings of ellipsoids become denser, and the coordination number increases slightly for oblate ellipsoids (aspect ratio between 0.25 and 0.75), but decreases for most of the prolate ellipsoids due to the conspicuous excluded volume effects. It is found that packings of ellipsoids are more random after vibration, showing opposite trend to spheres. The analysis of Voronoi tessellation for ellipsoids packing indicates that after vibration, some bridges or arches collapse, and particles reorganize to fill voids, leading to denser packings. The Voronoi cell volume becomes smaller for both oblate and prolate particles, and more uniform for oblate particles. Therefore, the bed becomes densely packed by obtaining smaller and more uniform Voronoi cell (or void structure) at the sacrifice of particle orientational order.

中文翻译：

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一维振动周期边界条件下椭球堆积结构分析

摘要 本文采用离散元法数值研究了一维振动和周期边界条件下椭球粒子的堆积结构。结果表明，振动后，椭球的堆积变得更加致密，扁椭球的配位数略有增加（长宽比在0.25和0.75之间），但由于明显的排除体积效应，大多数扁椭球的配位数减小。发现振动后椭圆体的堆积更加随机，与球体呈相反的趋势。椭球堆积的 Voronoi 镶嵌分析表明，振动后，一些桥梁或拱门坍塌，颗粒重新组织以填充空隙，导致堆积更密。对于扁长粒子和扁长粒子，Voronoi 细胞体积都变小，扁平颗粒更均匀。因此，通过牺牲粒子取向顺序获得更小、更均匀的 Voronoi 细胞（或空隙结构），床变得密集。