Abstract

Fabric of a granular assembly represents the topology of the contact network. This paper investigates the evolution of contact anisotropy (fabric) and average coordination number for a granular assembly subjected to uniaxial compression through the Discrete Element Method (DEM). A monosize three-dimensional random close-packed granular assembly with periodic boundary conditions under uniaxial compression is considered in this work. The fabric evolution is studied by post-processing the output data of the DEM simulation. The influence of cyclic loading, strain rate, and Young’s modulus on the evolution of contact anisotropy and average coordination number is presented. The Young’s modulus of the particle shows a significant influence on the particle contact creation during compression of the granular assembly with high strain rate. Effect of inertia on the contact anisotropy is observed to be significant during the compression of granular assemblies with different Young’s modulus under high strain rate. The paper concludes with a semi-empirical model to predict the evolution of contact anisotropy as a function of the macroscopic stress state of the assembly during quasi-static uniaxial compaction. The model also introduces two microscopic non-dimensional parameters that are independent of friction between the particles and can be used to relate the macroscopic stresses with the contact anisotropy.

Graphic abstract

中文翻译：

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在不同载荷条件下通过DEM影响的球形颗粒组件中织物的演变

摘要

粒状组件的结构代表了联系网络的拓扑。本文通过离散元方法（DEM）研究了单轴压缩的粒状组件的接触各向异性（织物）和平均配位数的演变。在这项工作中考虑了具有单轴压缩的周期性边界条件的单尺寸三维随机密堆积颗粒组件。通过对DEM模拟的输出数据进行后处理来研究织物的演变。给出了循环载荷，应变率和杨氏模量对接触各向异性和平均配位数的演变的影响。颗粒的杨氏模量在以高应变速率压缩粒状组件的过程中显示出对颗粒接触产生的显着影响。在高应变速率下，压缩具有不同杨氏模量的粒状组件时，惯性对接触各向异性的影响非常明显。本文以半经验模型得出结论，以预测准各向异性单轴压实过程中接触各向异性随组件宏观应力状态的变化。该模型还引入了两个微观无量纲参数，这些参数与粒子之间的摩擦无关，可用于将宏观应力与接触各向异性相关联。本文以半经验模型作为结论，以预测准各向异性单轴压实过程中接触各向异性随组件宏观应力状态的变化。该模型还引入了两个微观无量纲参数，这些参数与粒子之间的摩擦无关，可用于将宏观应力与接触各向异性相关联。本文以半经验模型得出结论，以预测准各向异性单轴压实过程中接触各向异性随组件宏观应力状态的变化。该模型还引入了两个微观无量纲参数，这些参数与粒子之间的摩擦无关，可用于将宏观应力与接触各向异性相关联。

图形摘要