DEM-Based Numerical Simulation of Rock Cutting Process Using Conical Pick Under Confining Stress Influence

With the increasing depth of underground resource extraction and underground space exploitation, rock characteristics and confining stress conditions have changed, which brings a serious challenge for mechanized excavation, such as heavy wear on cutters, serious dust pollution, and significant decline in mining efficiency. It leads to a substantial increase in the cost of mechanized excavation operation. Rock fragmentation mechanism is the core content for optimizing cutter design and improving mechanized excavation efficiency. Resulting from the discontinuity damage of the rock under the cutter action, Discrete Element Method (DEM) has become one of the effective methods to study the rock fragmentation mechanism. A conical pick cutter is a typical mechanized rock-cutting tool. In this study, a two-dimensional discrete element model for rock fragmentation using a conical pick was established to simulate the fragmentation performance of the rock under different confining stresses. The change of cutter force during the cutting process was monitored and recorded, as well as the volume of broken rock. Finally, by calculating and analyzing specific energy under different confining stress conditions, the optimal working state was explored to make the rock-cutting specific energy lowest. This study explores the influence of confining stress on rock cutting and reveals the rock fragmentation mechanism under confining stress.