Limpet radula-inspired triangular groove TBM cutter for hard rock breakage with low specific wear

The development of high-performance cutters that effectively break hard rocks without serious cutter wear is urgently required for tunnel boring machines (TBMs), but remains a key challenge. Herein, inspired by limpet radula, we present a biomimetic design strategy for creating a triangular groove cutter that exhibits strong hard rock-breaking capability and low specific wear. The bio-inspired triangular grooving on the cutting edge triggers a continuous impact action at the cutter-rock interface that enhances the rock-breaking capability of the cutter but aggravates cutter wear. The impact is negatively related to the grooved-edge length of the cutter, and by regulating the grooved-edge length, the cutter performs hard-rock breaking via a cutter-rock interaction combining rolling and impact and prevent itself from catastrophic wear. Discrete element analysis indicates that the bio-inspired triangular groove cutter induces the intersection of long cracks and the formation of large rock debris on the rock surface. Evidently, our biomimetic design strategy demonstrates great promise for high-performance TBM cutters.