Numerical simulation of rock fragmentation process by roadheader pick

A numerical model of rock fragmentation caused by a roadheader pick was established based on the particle flow code in two dimensions to study the rock fragmentation mechanism of the roadheader pick. The model simulated crack initiation, propagation and chip formation. The feasibility and reliability of the method as well as numerical model were verified by experiment. Results show that the rock fragmentation process includes three stages: crack initiation, crushing zone and radial crack formation, major tensile crack propagation and rock fragment formation. The crushing zone, number of radial cracks, specific energy consumption of rock cutting and dust level increase as the pick-tip corner radius increases. Consequently the pick-tip corner radius should range from 0 to 2 mm to obtain large rock fragments and low specific energy consumption. The damage of medium-hard and hard rock by the roadheader pick is more remarkable than that of soft rock. Furthermore, the sharp pick is suitable for the soft rock, whereas the pick tip with a proper rounding corner is perfect for the medium-hard and hard rock.