Chipping and crushing mechanisms in orthogonal rock cutting

• Published in: International journal of mechanical sciences Vol. 119; pp. 224 - 236
• Main Authors: Che, Demeng, Zhu, Wu-Le, Ehmann, Kornel F.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.12.2016
• Subjects: Analytical model; Chip formation; Chipping; Crushing; Cutters; Cutting; Cutting mechanics; Cutting parameters; Cutting theory; Mathematical analysis; Polycrystalline diamond compact (PDC) cutter; Rock; Rock cutting; Rock removal mechanism; Analytical model; Cutting mechanics; Rock cutting; Cutting theory; Polycrystalline diamond compact (PDC) cutter; Rock removal mechanism
• ISSN: 0020-7403; 1879-2162
• DOI: 10.1016/j.ijmecsci.2016.10.020

The understanding of rock removal mechanisms, as one of the essential elements for advancing the cutting performance of polycrystalline diamond compact (PDC) cutters, is still incomplete. This paper is seeking to formulate a cutting theory to analytically explain how rock interacts with PDC cutters in a simple cutting configuration – linear cutting. In the proposed approach, a rock crushing zone is introduced at the rock-cutter interface beneath the cutter's rake face, namely the Tip Crushing Zone (TCZ), which, as a destruction kernel, is responsible for both the crushing and chipping phenomena occurring in the cutting process. The physical aspects of these two disparate chip formation mechanisms are discussed. Moreover, closed form expressions for the cutting and thrust forces are derived based on the equilibrium of moments and on the minimum chipping energy principle. To evaluate the force model, comprehensive linear rock cutting tests were conducted on a newly developed rock cutting facility. Both the chip formation phenomena and force responses are in good agreement with the newly proposed theory. •A new cutting theory is proposed to explain rock's cutting and chipping mechanisms•Experimental data is presented in support of force and chip formation predictions.•The predictions of force responses and rock failure behaviors agree with the tests.•The theory provides insights into the optimization of rock cutting processes.