Design and structural optimization of a mole-claw-inspired bionic disc cutter

Abstract

Disc cutters, as advanced tools for hard-rock fragmentation, often exhibit reduced efficiency and accelerated wear under complex geotechnical conditions, which severely limits their service performance. While biomimetic principles have been widely applied to soil-engaging tools, a significant research gap remains regarding the systematic integration of macroscopic multi-curvature biological profiles into the core geometry of heavy-duty disc cutters for high-stress rock environments. To address this gap, this study proposes a biomimetic structural optimization strategy inspired by the excavation mechanics of the mole’s third claw toe. The novelty of this design lies in utilizing the claw’s transverse and longitudinal morphological profiles as a dynamic debris deflector, aiming to shift the rock fragmentation mode from inefficient compressive crushing to a more efficient tensile-shear failure. A systematic multistage optimization framework was established. Plackett–Burman design, steepest ascent experiments, and Box–Behnken Design combined with response surface methodology were sequentially applied to achieve global parameter optimization. The optimal structural configuration was determined as a tooth inclination angle of 5.9°, 67 teeth, and a tooth length of 5.54 mm. Performance was subsequently evaluated using a calibrated discrete element method coal-rock model coupled with the Archard wear model. Numerical simulation-based predictions indicate that, relative to a conventional cutter, the optimized bioinspired design achieves an 11.6% reduction in mean cutting force, a 15.47% reduction in wear volume, and a 9.8% decrease in specific cutting energy. These numerical outcomes provide a robust theoretical proof-of-concept for translating mole claw biomechanics into engineering design principles, establishing a solid foundation for future full-scale experimental verification and the development of high-efficiency excavation tools.