Abstract：To determine the optimal conditions of TBM disc cutters rock fragmentation, Combines the advantages of finite difference method (FDM) and discrete element method (DEM), and uses the FDM-DEM method to simulate the 3D dynamic TBM cutting rock model and analyze the optimal conditions under different spacing and penetration conditions. In order to verify the feasibility and accuracy of the proposed method, linear cutting tests were performed on Colorado red granite. The results show that: for the Colorado red granite, the mean normal force and rolling force of TBM disc cutter will first decrease and then increase with the increase of the ratio of the spacing to penetration. When the ratio of the spacing to penetration is about 20, the mean normal force and rolling force of TBM disc cutter are the minimum. Both the linear cutting test and the numerical simulation results show that when the ratio of spacing to penetration is around 17-20, the specific energy reach the lowest, and the TBM cutting efficiency is the highest at this time. The method proposed in this paper can provide an important basis for the configuration of TBM disc cutters.
