An improved continuum-based finite–discrete element method with intra-element fracturing algorithm

Abstract

This work develops a continuum-based combined finite–discrete element method (FDEM) in the framework of the explicit finite element method in conjunction with fracture algorithms. To account for complex fracturing processes, both shear failure and tensile failure criteria are implemented. Furthermore, to investigate the effect of different fracture algorithms on the accuracy and computational efficiency of simulations, both the inter-element and intra-element fracture algorithms are developed in the continuum-based framework. Then, they are compared by two benchmark tests, of rock: the Brazilian tests and uniaxial tension tests. Besides, uniaxial compression tests under different loading rates are carried out to demonstrate the shear failure criterion and the corresponding fracture algorithm.The simulation results converge with the decrease of element sizes in the inter-element fracture algorithm. The intra-element fracture algorithm is proven to be more efficient and accurate in the simulation of fracturing processes compared to the inter-element fracture algorithm.