Granular Matter ( IF 2.3 ) Pub Date : 2022-02-17 , DOI: 10.1007/s10035-022-01210-0 Mengmeng Wu 1 , Jianfeng Wang 1, 2 , Fanyu Wu 3
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Particle morphology is an essential characteristic that plays a crucial role in determining the mechanical responses of granular materials. A series of discrete element method (DEM) simulations of a mini-triaxial test were conducted, focusing on the shear behaviours of granular material. To mimic the physical testing situation, DEM simulations were combined with micro-computed tomography, and image processing techniques and spherical harmonics analysis were utilised to reconstruct realistic particle morphology. The multisphere clump method and flexible-membrane technique were used to simulate three types of sand and allow flexible deformation in the radial direction. The numerical results show that the grains inside the shear band rotate more freely and exhibit obvious fabric anisotropy. The shear behaviours are strongly associated with the shape of the component particles. Specifically, with the increase in shape irregularity, the stiffness and peak deviatoric stress increase, and a more obvious dilation is observed during shearing. In addition, with particles ranging from regular to angular, less particle rotation and more intense fabric anisotropy occur. The numerical investigations highlight the significant role of particle morphology in the shear behaviours of granular materials.
Graphical abstract
中文翻译：
颗粒形状对 DEM 模拟砂中剪切条带的影响
颗粒形态是一个基本特征，在确定颗粒材料的机械响应中起着至关重要的作用。对小三轴试验进行了一系列离散元法 (DEM) 模拟，重点关注颗粒材料的剪切行为。为了模拟物理测试情况，将 DEM 模拟与微型计算机断层扫描相结合，并利用图像处理技术和球谐分析来重建真实的粒子形态。采用多球团块法和柔性膜技术模拟三种砂体，并允许径向柔性变形。数值结果表明，剪切带内的晶粒旋转更自由，并表现出明显的织物各向异性。剪切行为与组分颗粒的形状密切相关。具体而言，随着形状不规则性的增加，刚度和峰值偏应力增加，并且在剪切过程中观察到更明显的膨胀。此外，颗粒从规则到有角，颗粒旋转更少，织物各向异性更强烈。数值研究突出了颗粒形态在颗粒材料剪切行为中的重要作用。
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