Finite Element Simulation Of The Mechanical Behavior On Coal Rock Cutting

Coal rock cutting is a complicated process between coal rock and pick. In order for the innovative design of shearer drum, the selection of the shearer and the cutting parameters, detailed study on mechanical behavior between coal rock and pick on the cutting process and the influence of cutting parameters on cutting performance is of great significance. This study can also be used in prolonging the working life of picks, enhancing the reliability of shearer and improving the economic benefits.A finite element model of coal rock cutting process using tensile and shear failure criterion was built up with the help of Abaqus/Explicit. Compared with cutting test, the cutting force of simulation had a good consistency with cutting test. When the cutting depth were 5, 10, 15 and 20 mm, The difference of the cutting force between simulation and test was 0.1%, 12%, 18.6%, 7.4%,respectively. The natural law during linear coal rock cutting process and the influence of cutting parameters on cutting performance were studied using this finite element model. The results show that the fragmentation process of coal rock can be divided into three stages: deformation stage, crack initiation stage, crack propagation stage. The chip formation was caused by the propagation of tensile(primary) and shear(secondary) cracks. The cutting force, the size of coal rock chip and the fluctuation of cutting force increase with the increasing of cutting depths. The peak frequency of the cutting force spectrum decreases with the increasing of cutting depths. The broken angle of coal rock is basically same with the increasing of cutting depths. The specific energy decreases then increases with the increasing of cutting depths, and the specific energy is minimum in the cutting depth of 80 mm. The cutting force, the size of coal rock chip, the broken angle of coal rock, the fluctuation of cutting force and the specific energy increase with the increasing of hardness of coal rock. The peak frequency of the cutting force spectrum decreases with the increasing of hardness of coal rock. The cutting force, the specific energy and the broken angle of coal rock is basically same with the increasing of cutting velocities. The peak frequency of the cutting force spectrum and the fluctuation of cutting force increase with the increasing of cutting velocities.A finite element model of coal rock rotary cutting process was built up based on Shangwan coal mine of Shenhua group, and the rotary cutting process was researched. The fragmentation process of coal rock during rotary cutting process can be divided into three stages: deformation stage, crack initiation stage, crack propagation stage. The specific energy decreased with the increasing of diameter of pick’s tip. The specific energy increased with the increasing of angle of pick’s body. The cutting force, the specific energy, and the fluctuation of cutting force increase with the increasing of hardness of coal rock.Within the range of 40-50°impact angle, the mean cutting force, the specific energy, and the fluctuation of cutting force decrease with the increasing of impact angle. The mean cutting force, the specific energy, and the fluctuation of cutting force was maximum in the impact angle 40°. The mean cutting force, the specific energy, and the fluctuation of cutting force was minimum in the impact angle 50°.