Abstract:
In order to explore the influence of mineral heterogeneity on the deformation localization and microcrack propagation of fractured coal-rock, the macroscopic deformation and fracturing process of fractured coal-rock during the testing were revealed from the microscopic scale based on the constructed discrete element numerical model considering mineral components. The localization characteristics of the stress field and the displacement vector field around the crack were analyzed using the measurement circle method. The research results show that under the same flaw inclination angle, the peak strength of fractured coal-rock first decreases and then increases with the increase of ligament angle. The penetration mode of fractured coal-rock changes from indirect penetration approximately parallel to axial tensile mixed failure to direct penetration of oblique shear-tensile failure. The initiation stress levels of meso-tensile and shear cracks are positively correlated with the flaw inclination angle. The initiation of compressive shear crack is later than those of tensile crack and tensile-shear crack. In addition, the compression localization area around the infilled flaws is larger than that of the non-infilled one, while the tensile localization area tends to be smaller.