Zou Qianjin, Li Haigang, Zheng Yu, Zhang Xinru, Wang Liuyue, Zhang Jiyong
School of Resources and Environmental Engineering, Jiangxi University of Science and Technology, Ganzhou, 341000, China.
Jiangxi Academy of Emergency Management Science, Nanchang, 330030, China.
Sci Rep. 2025 Mar 26;15(1):10451. doi: 10.1038/s41598-025-94232-6.
Microstructural damage is an important cause of macrofracture in fissured rocks. To investigate the microscopic fracture mechanism of fissured rocks, a fissured rock model was established using the CZM-FDEM method. The model considers the mechanical behaviour of cohesive elements between particles within the rock and the propagation of cracks through the damage of cohesive elements. In the damage evolution stage of the cohesive element ontological relationship, the damage variable D is introduced to describe the damage degree of the unit stiffness, which in turn characterises the microscopic damage features of the model. The results show that the stress-strain curve morphology and strength characteristics of the numerical model are in high agreement with the indoor test results, and the model exhibits significant advantages in crack extension, which verifies the applicability of the method in rock fracture simulation. The microscopic damage field exhibits X-shaped conjugate fracture characteristics, and the crack inclination leads to differences in fracture paths by changing the stress field distribution at the crack tip. The number of cohesive element fractures on the microscopic scale shows a high correlation with the macroscopic strength, and the cleavage inclination angle directly affects the load carrying capacity of the structure by regulating the fracture element rate.
细观结构损伤是裂隙岩石宏观断裂的重要原因。为研究裂隙岩石的细观断裂机理，采用CZM-FDEM方法建立了裂隙岩石模型。该模型考虑了岩石内部颗粒间粘结单元的力学行为以及裂纹通过粘结单元损伤的扩展。在粘结单元本体关系的损伤演化阶段，引入损伤变量D来描述单元刚度的损伤程度，进而表征模型的细观损伤特征。结果表明，数值模型的应力-应变曲线形态和强度特性与室内试验结果高度吻合，且该模型在裂纹扩展方面具有显著优势，验证了该方法在岩石断裂模拟中的适用性。细观损伤场呈现X形共轭断裂特征，裂纹倾角通过改变裂纹尖端的应力场分布导致断裂路径的差异。细观尺度上粘结单元的断裂数量与宏观强度具有高度相关性，劈裂倾角通过调节断裂单元率直接影响结构的承载能力。
