This paper proposes a numerical three-dimensional (3D) mesoscopic approach based on the discrete element method combined with X-ray computed tomography (XCT) images to characterize the dynamic impact behavior of heterogeneous coal-rock (HCR). The dynamic impact loading in three directions was modelled to investigate the effects of the 3D meso-structure on the failure patterns and fracture mechanism, with different impact velocities. The XCT image-based discrete element model of HCR was calibrated through appropriate standard uniaxial compression tests. Numerical simulations were carried out to investigate how the breakage behaviors are affected by different loading directions with different impact velocities. The loading direction, input energy, and spatial distribution of the mineral phase had a remarkable influence on the failure patterns and load-carrying capacities. The shape of the gangue phase and the approximate location of the gangue interfaces are key parameters to consider when investigating the failure patterns and fracture mechanism of heterogeneous rock materials. The damage and fracture tended to propagate from the surfaces to the HCR interior. The gangue phase area contacting the loading wall, growth direction of the strong gangue interfaces, and loading directions greatly influenced the failure patterns of the heterogeneous rock materials.

本文提出了一种基于离散元方法结合X射线计算机断层扫描（XCT）图像的三维三维（3D）介观方法，以表征非均质煤岩（HCR）的动态冲击行为。对三个方向的动态冲击载荷进行了建模，以研究3D细观结构对不同冲击速度下的破坏模式和断裂机理的影响。HCR基于XCT图像的离散元素模型通过适当的标准单轴压缩测试进行了校准。进行了数值模拟，以研究破损行为如何受到不同加载方向和不同冲击速度的影响。加载方向，输入能量，矿物相的空间分布对破坏模式和承载能力有显着影响。在研究非均质岩石材料的破坏模式和断裂机理时，脉石相的形状和脉石界面的近似位置是要考虑的关键参数。损伤和断裂倾向于从表面传播到HCR内部。煤the石的相面积与加载壁的接触，强growth石界面的生长方向和加载方向对非均质岩石材料的破坏模式有很大影响。损伤和断裂倾向于从表面传播到HCR内部。煤the石的相面积与加载壁的接触，强growth石界面的生长方向和加载方向对非均质岩石材料的破坏模式有很大影响。损伤和断裂倾向于从表面传播到HCR内部。煤the石的相面积与加载壁的接触，强growth石界面的生长方向和加载方向对非均质岩石材料的破坏模式有很大影响。