Mechanism and Experimental Research on Rock Breaking by Cutting Teeth of High-Speed PDC Drill Bit

In order to study the breaking mechanism of rock of high-speed PDC drill bits, improve the cutting efficiency of cutting teeth, and reduce the wear of cutting teeth, the rock-breaking process of PDC cutting teeth is simulated based on mechanical theory knowledge and experiments in this paper. And the influence of changes in PDC tooth rake angle, cutting depth, and diameter of the cutting tooth was studied by changing the different structural and cutting parameters of the cutting teeth, as well as the changes in cutting force, frictional resistance stress, and contact pressure on PDC teeth during the cutting process. The simulated results show that the total energy of the system increases, and the total energy of the system is the largest when cutting at 45°, which coincides with the maximum contact pressure on the teeth at this time. At the same time, it also shows that the impact resistance of PDC teeth is the strongest when chamfered at 45°. The contact area is also smaller, so the cutting is more conducive to the cutting tooth eating into the formation and prolonging the service life of the cutting tooth when the tooth rake angle is 20°. The experimental results showed that, in the actual design of PDC drill bits, an appropriate smaller side angle is not only beneficial for chip removal, but also helps to prevent lateral vibration and does not have a significant impact on cutting load. Finally, obtaining the relationship curve between structural parameters and rock properties is of great significance for guiding the design of PDC drill bits, understanding the intrinsic mechanism of rock fragmentation, and revealing the macroscopic nonlinear mechanical behavior of rocks.