Modification of a Rock Cuttability Theoretical Model for V-Shape Disc Cutter Considering the Edge Radius

Rock cuttability always has been recognized as one of the most effective parameters in selection and design of cutting tools and prediction performance of mechanical excavator machines. Field, experimental and theoretical methods have been applied into determination of rock cuttability. In this study, the theoretical model of rock cutting forces estimation presented for V-shape disc cutters was modified taking into account the influence of cutter edge radius. In order to validate the proposed model, full-scale rock cutting test data presented by Balci and Tumac (2012) and t-test with 99% interval confidence have been implemented. The results showed that there is a strong correlation between estimated rock cutting forces and real data, and since the p-value is more than α=0.01, both methods have the same values on average. To study the effect of edge radius of V-shape disc cutters, the proposed model was used. The results showed that for a constant edge angle, increasing edge radius increases cutting forces of blunt disc cutter more than those of sharp disc cutter. Also, with increase in penetration depth, the effect of edge radius on cutting forces diminishes in such a way that the cutting forces approach those of sharp disc cutter. In other hands, increasing edge angle caused a non-linear increase in blunt disc cutter cutting forces for a constant penetration depth.