Rock breakages caused by an asymmetric cutter and a constant cross-section cutter acting on precuts

Abstract

To reduce the cutting load and increase the cutting efficiency, laboratory and numerical tests involving a constant cross-section (CCS) cutter and an asymmetric cutter acting on precuts were performed. A laboratory study indicated that the asymmetric cutter consumes less energy than the CCS cutter under the same test conditions. In addition, the asymmetric cutter can ensure more effective rock breakages between precuts by generating oriented cracks. The numerical study results, which agree well with the laboratory test results for rock fractures, indicate that the plastic zones shrunken by the asymmetric cutter may be responsible for the decreased energy consumption. In addition, the dynamic stress evolution analysis reveals the fracture differences between the asymmetric cutter and the CCS cutter and further explains why the asymmetric cutter is more efficient.