Numerical investigation on rock fragmentation by cutting head of roadheader based on fracture mechanics

To investigate the mechanical behavior and load torque of the cutting head in the rock fragmentation process, a numerical model was developed based on fracture mechanics and finite element method. And then, rock fragmentation and factors influencing the force of cutting head were investigated. The good agreement of variation characteristics of cutting torque between experimental results and numerical values indicated that the numerical model was reliable and correct, and thus it could be a useful approach for simulating rock fragmentation. The cutting torque and its range of fluctuation increased with the feeding speed, but decreased with the slope of linear variation of slanting angle (SLVSA). Improving the rotation speed could reduce cutting torque, but its effect on torque fluctuation was inconspicuous. Regression equations between the characteristic index (CI) of cutting torque, feeding speed, rotation speed and SLVSA are given.