Hybrid finite-discrete modelling of dynamic fracture of rock under impact loads and resultant fragment grinding

A loading rate-dependent strength equation is implemented into a hybrid finite-discrete element method to model dynamic fracture of rock under impact loads and resultant fragment grinding. The hybrid method is firstly calibrated by modelling the dynamic fracture of rock in the dynamic Brazilian tensile strength tests and comparing the modelled dynamic fracture process and dynamic strength increasing factors with those in literatures. The hybrid method is then applied to study dynamic fracture and resultant fragment grinding in the dynamic shear test of rock joints under various loading rates. Finally, it is concluded that the hybrid finite-discrete element method is a valuable tool to study rock dynamic fracture and fragment grinding.