In this study, the effects of particle shape of rigid sand and soft rubber materials on macro-scale shear response were reasoned based on micro-scale parameters. For this purpose, first, the shape properties of three different sand and two different rubber samples were quantified using image processing techniques, and the contact model parameters were calibrated through physical experiments. The direct shear test was simulated in a two-dimensional discrete element software with realistic particle forms. The soft nature of rubber particles was reflected using body-centered cubic packing with a linear-parallel bond contact model. As a result, coordination number, distribution of contact forces (i.e., strong contact, and fabric anisotropy), and contact sliding were derived by the numerical analyses. It has been observed that the particle shape leads to distinctive micro-scale responses due to the variations in the stiffness of the contacts.

中文翻译：

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从颗粒形状和颗粒尺度变形效应角度研究砂橡胶颗粒混合物的微尺度剪切响应

在本研究中，基于微观尺度参数推理了硬砂和软橡胶材料的颗粒形状对宏观尺度剪切响应的影响。为此，首先使用图像处理技术量化三种不同沙子和两种不同橡胶样品的形状特性，并通过物理实验校准接触模型参数。直接剪切试验在二维离散元软件中以真实的颗粒形式进行模拟。使用具有线性-平行键接触模型的体心立方堆积反映了橡胶颗粒的柔软性质。结果，通过数值分析得出配位数、接触力分布（即强接触和织物各向异性）和接触滑动。据观察，由于接触刚度的变化，颗粒形状会导致独特的微观响应。