Discrete element modeling of the machining processes of brittle materials: recent development and future prospective

In recent years, the discrete element method (DEM) has been used to model bulk material, especially brittle materials (such as rocks, ceramics, concrete, ice, etc.) with various mechanical properties or responses by setting serials of contact properties (such as bonds) in the particle assembly. These bonds can withstand a certain amount of force and/or moment, so that the stresses executed in the bond can be used for determining the initiation and propagation of micro-cracks. There are increasing evidences over the last 20 years that the DEM is becoming an effective numerical method to simulate the cracking, crushing, and deformation of continuous media under external loads. The DEM has now been widely used in the field of processing and machining of rock, ceramic, concrete, and other brittle materials. In this paper, the theoretical principles, formulations, and contact models as well as the numerical solving processes of DEM are introduced. The applications of DEM for the machining processes of brittle and rigid materials such as ceramics are described and reviewed in detail, and the future development trend is also discussed.