Numerical Investigation on Rock Fragmentation Mechanism of Tricone Bits and Strategy for Parameter Selection

In surface mining, drilling operations serve as a key link between geological exploration and mineral extraction. To optimize rock fragmentation and improve fragmentation efficiency, this study employs a two‐dimensional discrete element method (2D‐DEM) model via PFC2D to simulate the rock‐breaking process of tricone bits, analyzing the effects of cutting speed, depth, and rock uniaxial compressive strength (UCS). Results indicate that increasing cutting speed refines particles by enhancing tensile failure, while the influence of depth on particle size strengthens with rock strength. Crack propagation rate decreases as UCS increases, and tensile crack propagation rate consistently exceeds shear rate, validating the dominance of tensile failure. Spearman correlation analysis reveals a significant negative correlation between particle size parameters and the tension‐shear ratio and a significant positive correlation between UCS and the ratio. Based on these findings, qualitative recommendations for parameter adjustment are proposed: for low‐strength rock, use high speed and small depth to refine particles via tensile failure; for high‐strength rock, adopt large depth and low speed to leverage shear action; and for balanced failure modes, employ medium speed and depth. This work provides a mechanistic basis for adaptive drilling parameter selection in open‐pit mines.