Discrete element modeling and simulation study on cutting rock behavior under spring-mass-damper system loading

Abstract

Based on the rock scratch test and the finite element model, the 2D discrete element rock cutting model is established in this paper. The model adopts spring-mass-damping system to load the cutter, which is different from the previous single cutter rock breaking model. In this way, the model can effectively reproduce the vibration and stick-slip phenomena in actual rock cutting and enable the simulation of rock breaking by an individual cutter under a horizontal impact load. Then, the effects of the vertical force on the cutter, the driving velocity, and the system stiffness on rock breaking and the stick-slip vibration of the cutter are studied. The results show that the stick-slip vibration is easy to occur under the conditions of larger weight on bit, lower driving speed and smaller system stiffness. Although an increase in the driving velocity of the system can significantly restrain stick-slip vibration, when cutting speed increases from 0.5 m s−1 to 2.5 m s−1, the specific energy consumption of rock breaking increases by 68.83% and the cutting depth decreases by 41.14%. In contrast, when the horizontal impact load is used to suppress the stick-slip vibration, it has less effect on the specific energy consumption of rock breaking and the cutting depth. This study provides a theoretical basis for suppressing stick-slip vibration and efficient rock breaking in well drilling.