Added Cutting Teeth to Promote Surface Crack Incisions for Cutting Sandstone

Abstract To promote surface crack incisions between indentations, we first prefabricated CCS (constant cross section) indenters and modified indenters by adding cutting teeth on the CCS indenters. The subsequent indentation tests, using the modified indenters and the CCS indenters, indicate that the modified indenters can effectively promote surface crack incisions, initiating from the contact points between the cutting teeth and the rock. In addition, the promoted surface crack incisions form more thick chips between indentations, whereas the consumed indentation energy of the modified indenters is close to that of the CCS indenter. Thus, the modified indenter can effectively promote indentation efficiency.