Investigating the cutting force of disc cutter in multi-cutter rotary cutting of sandstone: Simulations and experiments

The cutting forces of a disc cutter are of great significance for advancements toward the design of rock-cutting tools. Studies often model rock-breaking through the 2D analysis of the cutterhead pressure or a linear cutting test of single- or double-disc cutters. However, neither approaches accurately reflect the actual cutting pattern. In this study, two models were constructed for the numerical simulation of continuous multi-cutter rotary rock cutting: one for the modelling of sandstone with soft-to-medium hardness, and the other for the numerical calculation of rotary cutting based on the actual cutting motion of the disc cutter. The results were compared with those of similarity tests conducted in a laboratory. The normal force required by the disc cutter for breaking intact rock surfaces was observed to be greater than that for breaking the broken rock surfaces. Unlike in linear cutting, in multi disc rotary rock-breaking, the cutter applies lateral compression to the rock on both sides, thereby promoting crack extension and penetration. As the mounting radius of the disc cutter increases, the normal and rolling forces, as well as the cutting coefficient of the rolling force, increase; the side force decreases. Moreover, a low thrust and high torque are maintained by the cutterhead.