Three-dimensional hybrid continuous-discontinuous modelling of the failure process of rock in Brazilian tests

A three-dimensional (3D) fracture algorithm is implemented into a hybrid finite-discrete element method previously developed by the authors using a cohesive cracking model with an energy failure criterion to model the 3D transition from continuum to discontinuum during rock fracture. The newly developed 3D hybrid continuous-discontinuous method is then applied to model the fracture process of rock in the Brazilian tensile strength tests. After that, the obtained results are compared with those well documented in literatures to calibrate the development of the 3D fracture algorithm for the transition from continuum to discontinuum. Throughout this study, it is shown that the 3D hybrid continuous-discontinuous method is a valuable tool to investigate rock fracture and resultant fragment grinding behaviour. Compared with finite element method, the hybrid method is more robust in modelling rock failure, especially fracture, fragmentation, and fragment movements resulting in tertiary fractures while compared with discrete element method, the hybrid method is more versatile in dealing with irregular-shaped, deformable and breakable particles.