Numerical Simulation of Rock Cutting in Different Cutting Mode Using the Discrete Element Method

Qian-Qian Zhang ； Zhen-Nan Han ； Shao-Hui Ning ； Qiu-Zu Liu ； Rui-Wu Guo

《Journal of GeoEngineering》 10卷2期 (2015/08) Pp. 35-43

https://doi.org/10.6310/jog.2015.10(2).1

並列摘要

The paper presents numerical modeling of rock cutting tests by using the discrete element method (DEM). The particle assemblies were generated by the specimen-genesis procedure, representing Medium-grade chromite and three types of sandstone. The solid models of pick with rounded tip built by Pro/ENGINEER5.0 were imported into Particle Flow Code in 3 Dimensions (PFC^(3D)), then the models of rock cutting were established. The macro-properties of the particle assemblies were calibrated by modeling the unconfined compressive strength and Brazilian tests. The particle assemblies were cut by pick at a constant velocity in unrelieved and relieved cutting modes, the crack propagation was observed, and the forces acting on pick were monitored. The mean peak cutting forces in unrelieved cutting mode, the mean forces in relieved cutting mode and the ratio of peak to mean forces in both cutting mode obtained from numerical and experimental studies were compared respectively. It was concluded that the mean forces, mean peak forces and the ratio of peak to mean forces were predicted accurately in the numerical simulation. In addition, according to the analysis of the variations of forces with cutting distance, the mean cutting force and the mean normal force obtained in relieved cutting mode are lower than those in unrelieved mode, and an important conclusion can be drawn that the influence of the adjacent cut plays a substantial part during the cutting process. Furthermore, the figures showed that the number of cracks in tensile failure is about three times as large as in shear failure in this simulation, thus the fractures formed in the condition of tensile failure as the main failure mode. Based on this study, it is determined that DEM is a suitable method to carry out the simulation of rock cutting test and to observe the crack propagation.

並列關鍵字

Discrete element method ； solid models ； unrelieved cutting ； relieved cutting ； mean force ； tensile failure