A Rock Breaking Force Prediction Model and Method of Wear Evaluation of Shield Disc Cutter in Hard Rock Stratum

In this paper, the methods of theoretical analysis, numerical simulation and fuzzy comprehensive evaluation are used to investigate the force and wear behavior of disc cutter in the process of rock breaking, and the accurate prediction of wear degree is realized. First, this paper proposes an accurate calculation method of the rock failure area. Based on this method, a new model suitable for a constant cross-section disc cutter to predict the normal and rolling forces is then proposed. Furthermore, analysis and comparison of the wear of a single disc cutter and a double disc cutter under varying penetration conditions were conducted by a numerical simulation method, the simulation results showed that the wear amount of the single disc cutter between different penetration shows an obvious aggregation trend. In contrast, the wear of the double disc cutter demonstrated a linear increase as the penetration increased. Finally, the analytic hierarchy process, fuzzy comprehensive evaluation method, and variable-weight theory were used to evaluate the wear degree. The evaluation model was validated by a field case in a metro section.