Computational Modeling of Tool-Rock Frictional Contact With Anisotropic Damage

The mechanism of frictional contact is investigated between a blunt tool and quasi-brittle rocks with anisotropic damage. A recently developed anisotropic elasto-plastic-damage model is further validated using experimental results under monotonic and cyclic loadings for rocks and concrete. A finite element model of tool-rock frictional contact is validated by analytical results in the two asymptotic regimes of an elastoplastic rock. The mesh sensitivity is reduced using a fracture energy-based method for anisotropic damage. The tool-rock frictional contact is predominantly controlled by three dimensionless parameters: η η , ξ ξ , and ζ ζ , which characterize elastoplasticity, brittleness, and anisotropic damage, respectively. The newly introduced damage coefficient ζ ζ controls the ratio of damage in different directions. As the elastoplastic parameter η η increases with more plastic deformation, the dimensionless average contact stress Π Π ~ increases and then slightly varies before stabilizing. As the brittleness number ξ ξ increases in a more brittle mode, the contact stress Π Π ~ generally decreases. When the damage coefficient ζ ζ decreases from isotropic to anisotropic damage, the contact stress Π Π ~ generally increases. The magnitudes of the average contact stress in numerical modeling are closer to experimental results when considering anisotropic damage.