To examine the effect of the grain shape on the mechanical behavior of granular materials, a series of the three dimensional distinct element method (DEM) simulations of the true triaxial test were carried out under plane strain condition. Six kinds of clump elements with a different microscopic angularity using two or four spherical elements were generated base on a coefficient of form unevenness (FU) as a shape factor. The maximum mobilized internal friction angle, the formation of the shear band, and the structural anisotropy based on the principal fabric tensor were examined with the FU value. As a result, it is found that the relationship between the maximum mobilized internal friction angle, φ_max and the FU value corresponds linearly. As the grain shape became more spherical with the increase of the FU value, the shear band appeared less clearly. It was also found that because the specimen with the larger FU value caused more structural anisotropy, the structural anisotropy depends on the FU value. Thus, it can be said that the FU as the shape factor can be a practical criterion to evaluate the effect of the grain shape on the mechanical behavior of granular materials.

为了检查颗粒形状对粒状材料力学性能的影响，在平面应变条件下进行了一系列三轴真三轴试验的三维离散元方法（DEM）模拟。基于形状不均匀系数（FU）作为形状因子，使用两个或四个球形元素生成了六种具有不同微观角度的块状元素。使用FU值检查了最大动员内部摩擦角，剪切带的形成以及基于主织物张量的结构各向异性。其结果是，发现最大的关系动员内摩擦角，φ_最大值和FU值线性对应。随着FU值的增加，晶粒形状变得更球形，剪切带出现得不太清楚。还发现由于FU值较大的样品引起更大的结构各向异性，因此结构各向异性取决于FU值。因此，可以说作为形状因子的FU可以作为评估晶粒形状对粒状材料机械性能影响的实用标准。