Influence of Friction and Rake Angle on the Formation of Discontinuous Rock Fragments During Rock Cutting

Tribological properties during rock cutting under extremely high pressure and high temperature (HPHT) conditions are important in deep mining and drilling operations. In the present investigation, a rock fragmentation process is simulated during mechanical cutting of rock using an explicit finite element code, LS-DYNA. In the simulations, a rigid steel cutting tool of different rake angles was moved at different velocities against a stationary rock material. Rock material properties have been incorporated using an advanced damage constitute material model. In addition, the friction factors at the cutting tool–rock interface were varied in the contact model. The variation of cutting forces, stresses and rock fragment morphology have been investigated. Overall, the results indicate that the explicit finite element model is a powerful tool for simulating rock cutting and the fragmentation process. More specifically, the separation of rock fragments from the rock slab was accurately predicted using the numerical model. The rake angle was found to have significant influence on the fragment morphology during rock cutting. Moreover, the cutting forces and the discontinuous fragmentation process were strongly influenced by the friction and cutting velocity.