Dynamic response of rock mass during split Hopkinson pressure bar test: numerical simulation utilizing distinct element method

摘要

Dynamic responses of rock mass subject to high strain rate loadings by Split Hopkinson PressurernBar (SHPB) tests were analyzed utilizing distinct element method in the present paper. In order to investigaternthe discontinuum of the rock mass, a numerical SHPB test model based on two-dimensional ParticlernFlow Code (PFC2D) was established. Two approaches with regular and random assemblies for incident andrntransmitted bars were compared to account for dispersion caused by inertial effect. Additionally, the relationshipsrnbetween strain rate and peak strength were studied and the rate-sensitive behaviors were analyzed. Therndistinct element method implemented in Particle Flow Code provides an effective approach to observe microcracksrnevolution, failure process and stress wave propagation; this model also can be extended to higher strainrnrate tests such as more than 103, 104 and so on. Furthermore, the effects of joint parameters such as locations,rndirections, contact areas, as well as stiffness, are investigated and attempts are made to shed light on macroresponsernwith respect to discontinuum of rock mass, the results identify that the joints are closely related tornfailure modes, stress wave propagation and dynamic response of rock mass.