FINITE ELEMENT STUDY ON CHIP FORMATION AND FORCE RESPONSE IN TWO-DIMENSIONAL ORTHOGONAL CUTTING OF ROCK

The understanding of the rock-cutter interaction is essential for efficient rock cutting/drilling performed with polycrystalline diamond compact (PDC) cutters in petroleum engineering and gas exploration. Finite element modeling of the rock cutting process still remains a challenge due to the complex material properties of rock, rock fracture and chip formation phenomena and large force oscillations during the dominant brittle cutting mode. A finite element study was conducted to investigate the chip formation and force responses in two-dimensional orthogonal cutting of rock. The Drucker-Prager model that incorporates a simple shear strain failure criterion was exploited to simulate the interactions between the rock and the cutter. A fully instrumented rock cutting testbed was developed to enable the measurements of the three orthogonal force components and of the uni-axial acceleration in the cutting direction along rectilinear tool-paths to evaluate the simulation results. The chip formation phenomena and force response predictions derived by the FEM simulations were in good agreement with the experimental tests.