Theoretical and Experimental Studies on Rock Cutting Mechanisms

Rock excavators equipped with cutting functions, such as roadheaders, surface miners, and various coal mining machinery, are widely used in civil engineering and mine operations. In the design and development of these machines, numerous researchers have conducted theoretical, experimental, and numerical studies to understand the rock cutting mechanisms using bits. This review article summarized research trends and future challenges concerning rock cutting mechanisms, focusing on theoretical and experimental studies. First, the technical terminology for cutting processes of a chisel bit or a point attack bit was introduced, and various equations for calculating cutting resistance based on the two- or three-dimensional cutting theory were described in detail, including their background, derivation processes, and relationships. Then, recent experimental studies on the factors affecting cutting resistance of a point attack bit were reviewed while mentioning key achievements with a chisel bit. The law of similarity and the cutting processes of multi bits mounted on a rotating drum were also explained since they are essential for the design and development of actual rock excavators. Studies on cutting hard rocks and mining deep seafloor mineral resources are ongoing, and hence it will be necessary to clarify the rock cutting mechanisms under these complicated severe conditions with utilizing accumulated knowledge introduced in this review article.