Development of a GPGPU-parallelized 3-D FDEM with a novel implementation of the discrete fracture network generation and recognition algorithm

Discrete fractures exist widely in the natural environment. After interacting with each other, these fractures form the complex discrete fracture network (DFN). The DFN segments the rock into pieces and forms complex macro or micro structures in the rock and thus influences the whole mechanical properties of the rock mass. However, as one of the novel hybrid methods for simulating the solids fracturing, the combined finite-discrete element method (FDEM), is still lacking an effective algorithm to generate and recognize the DFN in the model. In this scenario, this paper proposes a novel algorithm to generate and recognize the discrete fracture network in the 3-dimensional (3-D) FDEM based on the general-purpose graphics processing unit (GPGPU). The newly proposed algorithm can generate the 3-D disc-shape DFN with ease after specifying the properties of the DFN. Verifications of generating and recognizing a single pre-setting DFN are carried out to prove the correctness and effectiveness of the newly developed algorithm. Single-hole blasting simulations in the cubic granite samples with different amounts of discrete fractures are also conducted. It is concluded that the developed FDEM has the capability of simulating the discrete fracture network with specific DFN features, which paves the way for the 3-D FDEM to simulate the engineering problem with complex geo-structures.