Particle shape affects the mechanical properties of sands, but the underlying micro-mechanisms are not yet explored, at least partially, due to difficulties in accessing the particle scale information in the laboratory. This study aims to fill this gap through DEM by proposing a general framework for DEM simulation considering realistic particle shape and grading characteristics. Within the proposed framework, the irregular sand particle is approximated by 3D clump, and numerical triaxial drained compression tests are conducted for five granular assemblies of different overall regularity. The simulated critical state friction angles of these five assemblies are consistent with those predicted by an empirical formula proposed in the literature. The simulation results demonstrate that decreasing of overall regularity enhances the interlock effect between particles, making the assembly a higher stiffness and shear strength. Moreover, among different fabric anisotropies, the anisotropies of contact normal and normal contact force fabrics contribute to about 80% of the critical shear strength regardless of the overall regularity. With the decreasing of the overall regularity, the contribution of the anisotropy of contact normal fabric increases while that of normal contact force fabric decreases. The overall regularity mainly affects the anisotropies of contact normal and shear contact force fabrics.

颗粒的形状会影响沙子的机械性能，但是由于很难在实验室中访问颗粒尺寸信息，因此至少尚未部分研究潜在的微观机制。这项研究旨在通过提出考虑实际颗粒形状和分级特性的DEM模拟通用框架来填补DEM的空白。在提出的框架内，用3D团块近似不规则的沙粒，并对五个具有不同整体规则性的粒状组件进行了数值三轴排水压缩试验。这五个组件的模拟临界摩擦角与文献中提出的经验公式预测的相符。仿真结果表明，降低整体规则性可增强粒子之间的互锁效果，从而使组件具有更高的刚度和剪切强度。而且，在不同的织物各向异性中，接触法向和法向接触力织物的各向异性贡献了临界剪切强度的约80％，而与总体规则性无关。随着总体规则性的降低，普通接触织物的各向异性的贡献增加，而普通接触力织物的各向异性的贡献减小。总体规则性主要影响接触法向织物和剪切接触力织物的各向异性。接触法向和法向接触力织物的各向异性贡献了大约80％的临界剪切强度，而与总体规则性无关。随着整体规则性的降低，正常接触织物的各向异性的贡献增加，而正常接触力织物的各向异性的贡献减小。总体规则性主要影响接触法向织物和剪切接触力织物的各向异性。接触法向和法向接触力织物的各向异性贡献了大约80％的临界剪切强度，而与总体规则性无关。随着整体规则性的降低，正常接触织物的各向异性的贡献增加，而正常接触力织物的各向异性的贡献减小。总体规则性主要影响接触法向织物和剪切接触力织物的各向异性。