Tunnel boring machines (TBMs) require a large thrust and suffer from extensive cutter wear when tunneling in hard rock stratum. Controlling the cutter-rock contact by using an appropriate contact surface design can potentially improve the cutting performance of TBM cutters. This paper proposes a design scheme of disc cutters with surface grooves and uses a hybrid discrete element model and a reduced-scale rock-cutting experiment to evaluate the cutting performance of the proposed cutter. The results show that at the same penetration depth, the cutting force required by the grooved cutters is lower than that of the conventional flat-top cutter, and the rock chip volume decrease is not significant. Thus, the rock-cutting specific energy is reduced. The grooved cutter has a discontinuous contact area with the rock, reducing the volume of the crushed zone and the rock powder; thus, less energy is required for rock cutting. Wear experiments are performed to evaluate the durability of the pro-posed cutter. The results indicate that the tooth tips of the spiral groove cutter suffer plastic deformation in the first several hundred cycles, leading to a larger diameter decrease than that of the flat-top cutter. However, the two cutters have similar wear rates after the run-in period, and adhesive wear is the dominant wear mechanism of both cutters. This study demonstrates the feasibility of improving the cutter performance by changing the surface structure, providing a new strategy for increasing the driving speed of TBMs in a hard rock stratum.
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