Numerical Simulations and Experiments on Single-Tooth Rock-Breaking

The rock-breaking efficiency of a drilling tool directly affects the production costs and progress of foundation construction. It is essential to understand the mechanism of mechanical rock-breaking to improve rock-breaking efficiency. In this study, dynamic rock-breaking simulation research was carried out on a drill bit and was based on the LS-DYNA simulation platform. Additionally, the influence of the rotational speed of the spindle and the feed rate on the force of the drill bit in the rock-breaking process was obtained. The influence of the rotational speed of the spindle and the feed rate on drill vibration was also analyzed. The content of the presented theoretical and simulation research was verified through experiments. The following conclusions were drawn: first, the reaction force that rock has on the drill bit presents a law according to different rock types and drilling process parameters. With the increase in rotational speed, the axial reaction force decreases. With the increase in the feed rate, the axial reaction force increases. The effect of rock type on axial reaction force is nonlinear. Second, the influence of the spindle rotational speed and feed rate on the vibration of the drill bit also presents a law during rock-breaking. When the feed amount is constant, the transverse vibration slows down, and the axial vibration intensifies as the rotational speed increases. When the rotational speed is constant, as the feed increases, the transverse vibration slows down and the axial vibration intensifies. The research results provide a theoretical basis for selecting drilling process parameters and for improving rock-breaking efficiency.