Effects of shape and size polydispersity on strength properties of granular materials
Effects of shape and size polydispersity on strength properties of granular materials
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DOI：
10.1103/physreve.91.032203
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发表时间：
2015-03-18
影响因子：
2.4
通讯作者：
Radjai, Farhang
中科院分区：
文献类型：
--
作者：
Duc-Hanh Nguyen;Azema, Emilien;Radjai, Farhang
通过广泛的接触动力学模拟，我们分析了颗粒尺寸和颗粒形状的多分散性的综合影响，定义为形状的不规则度，剪切颗粒材料的剪切强度和微观结构组成的五边形颗粒。我们发现，剪切强度是独立的尺寸跨度，但出乎意料的是，它随着形状多分散性的增加而下降。同时，固体分数是尺寸跨度和形状多分散性的增函数。因此，密排填料和松排填料具有相同的剪切强度。在粒子及其接触的尺度上，我们分析了粒子的连通性、力的传递、摩擦的移动以及它们的各向异性。我们表明，更强的力是由更大的粒子和越来越多的小粒子支撑。剪切强度与尺寸跨度的独立性被证明是接触网络自组织的结果，与接触各向异性的衰减补偿增加力的各向异性。
By means of extensive contact dynamics simulations, we analyze the combined effects of polydispersity both in particle size and in particle shape, defined as the degree of shape irregularity, on the shear strength and microstructure of sheared granular materials composed of pentagonal particles. We find that the shear strength is independent of the size span, but unexpectedly, it declines with increasing shape polydispersity. At the same time, the solid fraction is an increasing function of both the size span and the shape polydispersity. Hence, the densest and loosest packings have the same shear strength. At the scale of the particles and their contacts, we analyze the connectivity of particles, force transmission, and friction mobilization as well as their anisotropies. We show that stronger forces are carried by larger particles and propped by an increasing number of small particles. The independence of shear strength with regard to size span is shown to be a consequence of contact network self-organization, with the falloff of contact anisotropy compensated by increasing force anisotropy.