Polyarc discrete element for efficiently simulating arbitrarily shaped 2D particles
Polyarc discrete element for efficiently simulating arbitrarily shaped 2D particles
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DOI：
10.1002/nme.3254
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发表时间：
2012-02
影响因子：
2.9
通讯作者：
P. Fu;O. Walton;J. Harvey
中科院分区：
文献类型：
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作者：
P. Fu;O. Walton;J. Harvey
本文提出了一种新的二维离散单元类型，称为“多弧”单元。与其他离散单元类型相比，新单元能够使用少量的形状参数来表示具有任意角度和伸长的任何二维凸颗粒形状。多弧元素之间的接触解析是DEM模拟中计算量最大的任务，仅涉及简单的闭合解。多圆弧单元避免了多边形单元中常见的两种不理想的接触情况，因此多圆弧单元的接触分解算法比多边形单元的接触分解算法简单。粒子形状表示的额外灵活性导致很少或没有额外的计算成本。介绍了该单元的关键算法，包括粒子形状表示方案、快速邻域搜索算法、接触分辨算法和接触律。在对多边形离散单元的各种接触律方案进行评价的基础上，提出了多圆弧模型的推荐接触律。新的元素类型的能力和效率进行了证明，通过调查的虚拟砂的强度各向异性组成的随机混合的角度和光滑的细长颗粒进行双轴压缩试验。版权所有© 2011约翰威利父子有限公司.
A new two‐dimensional discrete element type, termed the ‘polyarc’ element is presented in this paper. Compared to other discrete element types, the new element is capable of representing any two‐dimensional convex particle shape with arbitrary angularity and elongation using a small number of shape parameters. Contact resolution between polyarc elements, which is the most computation‐extensive task in DEM simulation only involves simple closed‐form solutions. Two undesirable contact scenarios common for polygon elements can be avoided by the polyarc element, so the contact resolution algorithm for polyarc elements is simpler than that for polygon elements. The extra flexibility in particle shape representation induces little or no additional computational cost. The key algorithmic aspects of the new element, including the particle shape representation scheme, the quick neighbor search algorithm, the contact resolution algorithm, and the contact law are presented. The recommended contact law for the polyarc model was formulated on the basis of an evaluation of various contact law schemes for polygon type discrete elements. The capability and efficiency of the new element type were demonstrated through an investigation of strength anisotropy of a virtual sand consisting of a random mix of angular and smooth elongated particles subjected to biaxial compression tests. Copyright © 2011 John Wiley & Sons, Ltd.