Geometry and force modeling, and mechanical properties study of polycrystalline diamond compact bit under wearing condition based on numerical analysis

Abstract

Polycrystalline diamond compact bit has been used in more than 90% drilling length all over the world. Tooth wear is the main factor reducing the service life and performance of the polycrystalline diamond compact bit. In this article, the mechanical properties of polycrystalline diamond compact bit under wearing conditions are studied. The geometric model of the worn and unworn cutters is built. A numerical method to address the cutting parameters of cutters is first proposed. Then the effects of wearing degrees and the penetration per revolution of polycrystalline diamond compact bit on cutting parameters, forces, and wear conditions are discussed. The result shows that the numerical method can be utilized to obtain the force conditions of cutters, predict the wear trends of polycrystalline diamond compact bit, and optimize the cutter layout design. The effect of penetration per revolution on the mechanical properties of polycrystalline diamond compact bit and cutters is very limited. Under a constant penetration per revolution, the cutting section area almost keeps a constant with the increase of wearing degree; the direction of the transverse force keeps unchanged. The force conditions are closely related to cutting arc length and the wear degree.