Abstract:
The rock mass can be assumed to homogeneous material from a macroscopic view, it is the heterogeneous material in mesoscopic scale and its physico-mechanical properties are discontinuous in space. The failure of jointed rock mass was usually caused by the initiation, propagation and coalescence of new wing cracks derived from primary joint. For more in-depth study of rock fracture instability, we need to study the expansion of rock cracks under external loads from the macro-meso perspective. This paper, based on the manifold cover concept, proposes a new discrete element numerical method, Manifold Lattice Discrete, combining with the particle contact model, introduced concept of stress boundary. The proposed method can easily simulate the generation，propagation and coalescence of rock crack from the macro-meso perspective. The whole process of rock fragmentation is thereafter reproduced. By analyzing the manifold cover and ball particle model, this paper constitutes the sphere unit cover function of three-dimensional manifold cover, establishes tetrahedron units, and obtains the equilibrium equation and compatible equation of the MLD model. For rock-like brittle material, crack propagation process can be simulated.
