Review of modeling tool‒rock frictional contact with a blunt PDC cutter

The mechanisms of tool‒rock frictional contact are reviewed, with a focus on recent advances in numerical modeling. An idealized problem is defined for tool‒rock frictional contact with a rigid blunt tool sliding on the surface of a half-space. The governing dimensionless parameters are summarized for rocks characterized by various rock material models. For elastoplastic rock, the mechanism of frictional contact is governed primarily by an elastoplastic parameter $\eta$, which contrasts a characteristic elastic stress with a yield strength. For poroelastoplastic rocks, the mechanism is controlled by both $\eta$ and $\text{λ}$, where $\text{λ}$ is a dimensionless parameter representing the ratio between a geometrical length scale and a characteristic dimension with pore pressure perturbation. For quasibrittle rocks with induced isotropic damage, the mechanism is controlled by both $\eta$ and $\xi$, where $\xi$ is a dimensionless brittleness number that contrasts a geometrical length scale with a material length scale. For anisotropic damage, the mechanism is governed by $\eta$, $\xi$, and $\zeta$, where $\zeta$ is the damage coefficient that controls the ratio of damage in different directions. The influence of these governing dimensionless parameters on the dimensionless average contact stress $\tilde{\Pi }$ is summarized in different regimes.