砂土颗粒三维形状模拟离散元算法研究

Algorithm for modelling three-dimensional shape of sand based on discrete element method

砂土颗粒形状对砂土宏观性质具有重要的影响。砂土颗粒形状的量化和构造是本文研究的主要内容。在离散元重叠颗粒族ODEC(overlapping discrete element cluster)方法的基础上提出了一种新的基于加权圆度的处理方法。首先是利用颗粒三视图提取二维圆度信息并对其进行加权平均,得到反映颗粒三维形状特性的加权圆度;然后在Matlab中创建具有指定加权圆度的三维凸包,对凸包进行体素化和骨架化处理后提取颗粒的三维空间信息;再利用PFC3D重建具有指定形状的clump块体,生成不同外轮廓特性的颗粒组,以此模拟各种形状的砂土颗粒。

The mechanical properties and characteristics of sand are significantly affected by particle shape. This paper is mainly aimed to quantify and build the grain shape. A new method based on ODEC(overlapping discrete element cluster) method is proposed. Firstly, the two-dimensional roundness of a particle in three projection planes is extracted through photography, and the weighted average roundness is calculated. Then the weighted average roundness is employed of particles to generate particles with various irregular shapes in numerical model through Matlab code and clump block function of PFC3 D.