A numerical study is conducted using the improved continuum-based discrete element method (CDEM) to investigate the effect of holes on the dynamic fracturing of multi-flawed rocks. The specimen geometries contain a perpendicular crack-like flaw, a hole-like flaw, and an inclined crack-like flaw. A fracture model is implemented into the improved CDEM that combines the nonlinear pressure-dependent shear strength and tensile strength of rocks. The digital image correlation method combined with ultra-high-speed photography is applied in a split Hopkinson pressure bar system to verify the accuracy of the proposed model. The experimental results show that the improved CDEM accurately reproduces dynamic crack behavior in rocks. The simulation results show that hole-like flaws significantly affect crack behavior compared with the two investigated crack-like flaws. However, this effect gradually weakens with increasing loading stresses. This study provides important insight into the dynamic fracturing of multi-flawed rocks.

中文翻译：

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孔洞对多缺陷花岗岩动态压裂影响的数值研究

使用改进的基于连续介质的离散元方法（CDEM）进行数值研究，以研究孔对多缺陷岩石动态压裂的影响。试样几何形状包含垂直裂纹状缺陷、孔状缺陷和倾斜裂纹状缺陷。将裂缝模型实施到改进的 CDEM 中，该模型结合了岩石的非线性压力相关剪切强度和拉伸强度。将结合超高速摄影的数字图像相关方法应用于分体式霍普金森压杆系统，验证所提模型的准确性。实验结果表明，改进的 CDEM 准确地再现了岩石中的动态裂纹行为。模拟结果表明，与两个研究的裂纹状缺陷相比，孔状缺陷显着影响裂纹行为。然而，这种影响随着加载应力的增加而逐渐减弱。这项研究为多缺陷岩石的动态压裂提供了重要的见解。