By utilizing numerical models and simulation, insights about the fracture process of brittle heterogeneous materials can be gained without the need for expensive, difficult, or even impossible, experiments. Brittle and heterogeneous materials like rocks usually exhibit a large spread of experimental data and there is a need for a stochastic model that can mimic this behaviour. In this work, a new numerical approach, based on the Bonded Discrete Element Method, for modelling of heterogeneous brittle materials is proposed and evaluated. The material properties are introduced into the model via two main inputs. Firstly, the grains are constructed as ellipsoidal subsets of spherical discrete elements. The sizes and shapes of these ellipsoidal subsets are randomized, which introduces a grain shape heterogeneity Secondly, the micromechanical parameters of the constituent particles of the grains are given by the Weibull distribution. The model was applied to the Brazilian Disc Test, where the crack initiation, propagation, coalescence and branching could be investigated for different sets of grain cement strengths and sample heterogeneities. The crack initiation and propagation was found to be highly dependent on the level of heterogeneity and cement strength. Specifically, the amount of cracks initiating from the loading contact was found to be more prevalent for cases with higher cement strength and lower heterogeneity, while a more severe zigzag shaped crack pattern was found for the cases with lower cement strength and higher heterogeneity. Generally, the proposed model was found to be able to capture typical phenomena associated with brittle heterogeneous materials, e.g. the unpredictability of the strength in tension and crack properties.

通过利用数值模型和模拟，无需进行昂贵、困难甚至不可能的实验，即可深入了解脆性异质材料的断裂过程。像岩石这样的脆性和异质材料通常表现出大量的实验数据，因此需要一个可以模拟这种行为的随机模型。在这项工作中，提出并评估了一种基于键合离散元方法的新数值方法，用于建模异质脆性材料。材料属性通过两个主要输入引入模型。首先，将晶粒构​​造为球形离散元素的椭球子集。这些椭圆体子集的大小和形状是随机的，这引入了颗粒形状异质性其次，晶粒组成粒子的微观力学参数由威布尔分布给出。该模型应用于巴西圆盘测试，其中可以针对不同组的颗粒水泥强度和样品非均质性研究裂纹萌生、扩展、合并和分支。发现裂纹萌生和扩展高度依赖于非均质性和水泥强度的水平。具体而言，在水泥强度较高和非均质性较低的情况下，从荷载接触开始的裂缝数量更普遍，而在水泥强度较低和非均质性较高的情况下，发现更严重的锯齿形裂缝模式。一般来说，