Development of a GPGPU-parallelized FDEM based on extrinsic cohesive zone model with master-slave algorithm

This paper proposes a novel general-purpose graphic-processing-units (GPGPU) parallel computing approach to an extrinsic cohesive zone model (ECZM) - based combined finite-discrete element method (FDEM) for simulating rock fracturing. The proposed GPGPU-parallelized ECZM-FDEM incorporates a master–slave algorithm as an alternative to the complex adaptive remeshing process, which is usually used in ECZM but has prevented it from being parallelized using GPGPU. Numerical experiments of the Brazilian test and uniaxial compression test of rocks are conducted to compare the proposed ECZM-FDEM with a GPGPU-parallelized FDEM using the intrinsic cohesive zone model (ICZM-FDEM). Results show that the proposed method can not only overcome the accuracy degradation of calculated stresses and deformations that is inevitable in ICZM-FDEM but also reasonably simulate rock fracturing. Moreover, the proposed GPGPU-parallelized ECZM-FDEM achieves a maximum relative speed-up of 13 times over GPGPU-parallelized ICZM-FDEM due to efficient contact calculations and larger stable time steps. Thus, the proposed ECZM-FDEM is more physically sound and more computationally efficient compared with ICZM-FDEM, which may contribute to the further developments of FDEM.