The Weibullian behavior of single grain crushing strength was investigated experimentally and numerically with the aim of enhancing the understanding of rock grain breakage. The morphologies of pebble grains were obtained using white light 3D laser scanning and image processing. A grain shape library was constructed for grain shape analysis with different shape descriptors. The use of the shape library and grain stability analysis is discussed for a suggested procedure to rotate a grain to its most stable configuration. Single grain crushing tests were performed for 30 pebbles to obtain force-displacement curves and fracture patterns. Each grain was compressed diametrically between flat platens. As expected, the values of the stress at bulk fracture follow a Weibull distribution. A procedure for generating crushable agglomerates with realistic particle shapes was demonstrated, which was accomplished in the discrete element modeling (DEM) of the single grain crushing test. The work presented here is novel in that both the heterogeneous micro-structures and randomly distributed flaws are considered. The DEM results demonstrate that the proposed modeling approach and calibrated parameters are reliable and can reflect the crushing behavior of rock pebbles. Finally, three parametric studies were presented evaluating the effects of micro-crack density, micro-crack disorder, and grain morphology on the Weibullian behavior of the crushing strength, none of which has previously been thoroughly considered. These three studies provide a deeper insight into the origin of the Weibullian behavior of single grain crushing strength.

实验和数值研究了单粒抗压强度的威布尔行为，目的是增强对碎石破碎的认识。使用白光3D激光扫描和图像处理可获得卵石颗粒的形态。构建了具有不同形状描述符的晶粒形状库，用于晶粒形状分析。讨论了形状库和晶粒稳定性分析的使用，以便将晶​​粒旋转到其最稳定的构型。对30个卵石进行了单粒破碎测试，以获得力-位移曲线和断裂模式。在平板之间沿直径方向压缩每个颗粒。如预期的那样，整体断裂时的应力值遵循威布尔分布。演示了生成具有实际颗粒形状的可破碎附聚物的过程，该过程在单颗粒破碎测试的离散元素建模（DEM）中完成。这里提出的工作是新颖的，因为考虑了异质的微观结构和随机分布的缺陷。DEM结果表明，所提出的建模方法和标定参数是可靠的，并且可以反映出卵石的破碎特性。最后，提出了三项参数化研究，评估了微裂纹密度，微裂纹紊乱和晶粒形态对威布尔式抗压强度行为的影响，而此前尚未对它们进行全面考虑。这三项研究提供了更深入的了解单颗粒抗压强度的威布尔式行为的起源。