Rock cutting with an actuated disc: An experimental study

Actuated Disc Cutter is an undercutting disc, which is dynamically actuated while being dragged across the rock surface. In simple terms, undercutting discs are roller disc cutters that are used like drag tools to undercut rocks. This mechanism allows to combine the robustness of a roller disc (low wear rate) with the effectiveness of a drag tool (low cutting forces). Even though various realizations of the undercutting concept and actuated cutters exist in equipments designed to mechanically excavate hard rocks, the rock failure mechanism and its influencing factors are still not well understood for this class of cutting tools. This paper reports an experimental study of an actuated cutting process, which was designed to evaluate a recently proposed kinematics-based model. This model leads to a prediction of the force variation on the cutter during an activation cycle, assuming either ductile or brittle failure of the rock. Experiments were conducted using CSIRO's actuated disc cutting test-unit, dubbed as Wobble, to test the theoretical predictions at various operating conditions. The excellent agreement between the model predictions and Wobble experimental data provides strong support for the theoretical model and the assumed laws governing the cutting process.