Rock Adaptability of TBM Variable Cross-section Cutter Ring Based on Finite Element Simulation

A cutter ring is a consumable tool used by a tunnel boring machine (TBM) to break rock, affecting the cost and time limit of tunnel engineering. In this paper, based on the working principle of the cutter ring, the failure form of cutter rings, and the mechanical properties of rock, a variable cross-section (VCS) cutter ring is optimized based on the existing constant cross-section (CCS) cutter ring. The finite element method was used to model the Beishan granite, and the mechanical properties of the granite were simulated. The average discrepancy rate of the four key parameters was 1.19% compared with the experimental results. The linear rock cutting experiment of the disc cutter in Beijing University of Technology was simulated, the simulation results of normal force are similar to the reality. The digital models of the 20-in CCS cutter ring and 30 types of VCS cutter rings are established, and modal, impact response, and cutting rock simulations are conducted. The results demonstrate that the natural frequencies of the two types of cutter rings are very close to 6.72 rad/s, confirming the feasibility of interchange. The impact resistance of most of the 30 VCS rings is higher than that of CCS rings, and the rock-breaking effect of all VCS rings outperforms that of the CCS rings. The VCS ring with the highest crushing adaptability of the rock model in this simulation experiment was obtained by statistical analysis of 3D data. This experimental method of rock adaptability can obtain the optimal design parameters of VCS cutter rings for a particular rock model. VCS cutter rings have the potential to support establishing a tool selection system with rock adaptability based on extensive experimental data in the future.