Document Type : Original Research Paper

Authors

• Shahin Fattahy ¹
• Ebrahim Farrokh ²

¹ Amirkabir University of Technology

² Amirkabir University of Technology (Polytechnic of Tehran)

Abstract

Accurate prediction of normal and rolling forces on TBM disc cutters is essential for optimizing cutter design and improving excavation efficiency in hard rock tunneling. Laboratory linear cutting tests are costly and time-consuming; therefore, a robust numerical alternative is required. In this study, a fully three-dimensional multi-disc cutting model was developed in LS-DYNA to simulate an A30581 disc cutter acting on Colorado Red Granite. Two constitutive models (Johnson–Holmquist Concrete – JHC and Riedel–Hiermaier–Thoma – RHT) were combined with two numerical schemes: pure Lagrangian and coupled Smoothed Particle Galerkin (SPG)–Lagrangian. Nine combinations of cutter spacing (25, 51, and 76 mm) and penetration depth (1.9, 3.8, and 6.4 mm) were analyzed. The coupled SPG–Lagrangian approach with the JHC model produced the highest accuracy, with average errors below 5% for normal force and approximately 10% for rolling force. In contrast, the pure Lagrangian–RHT combination yielded significantly larger deviations, especially in rolling force (errors exceeding 100% in several cases). The coupled SPG–Lagrangian method also reduced computational cost relative to full-SPG simulations and eliminated the need for arbitrary element erosion criteria. While the proposed framework reliably predicts cutting forces, further refinements are still required to accurately capture damage zones and crack propagation patterns. The results provide clear guidance for selecting constitutive models and numerical schemes in future TBM cutter simulations.

Keywords

• rock cutting
• LS-DYNA
• smoothed particle Galerkin
• Johnson-Holmquist concrete
• RHT

Main Subjects

• Mechanized Excavation