Modified Model for TBM Disc-Cutter Performance Prediction Considering Variable Penetration
Precisely predicting the forces acting on the disc cutters employed in tunnel boring machines (TBMs)—namely, the normal force (FN) and rolling force (FR)—is critical for optimizing their excavation performance and service life. Existing models for cutter performance prediction are primarily based on static or average penetration (P), rendering them inadequate for operating conditions where the penetration varies during excavation. Consequently, these models have limited accuracy and engineering applicability under complex, heterogeneous geological conditions. To address this challenge, this paper proposes a novel predictive model capable of adapting to variable penetration to more accurately predict the disc-cutter performance. Based on indoor linear cutting rock test data from 21 distinct rock samples and combined with ABAQUS numerical simulations, the coupled mechanisms between TBM disc-cutter cutting parameters were systematically analyzed. Subsequently, a modified dual-force prediction model for FN and FR was developed, incorporating a dimensionless correction factor κ to enhance the accuracy of the ratio FR/FN. Validation results showed that compared with eight conventional predictive models, the proposed framework achieved a 44.31% reduction in the mean relative error under low-to-medium-strength rock conditions, demonstrating its superior reliability in predicting the strength within these specific geological regimes. This research provides theoretical and practical insights for accurately predicting disc-cutter forces under complex geological conditions, thus improving excavation efficiency and durability optimization of TBMs.