Simulation of force chains and particle breakage of granular material by numerical manifold method

Force-chain is the main load-bearing structure in the granular materials. The study of force chains and particle breakage is of great significance to understand the mechanical properties of the granular materials. At present, the internal relationship between the force chains and particle breakage is still unclear. It also has no idea about the crushing mode of the particle system with complex gradation and stress path. Therefore, in the present paper, the continuous-discontinuous numerical method (Numerical Manifold Method, NMM) is utilized to simulate the process of the force chains generation and particle breakage in granular material and to explore their internal connection mechanism. The simulation results show that the particle breakage is directly related to the force-chain network, and the particle breakage morphology is basically consistent with the direction of the force-chain network in the granular system. Small particles are broken firstly, producing large displacement to fill the voids in the system. Although the larger particles can also be broken, it is difficult to produce large displacement due to the influence of coordination number among particles. Furthermore, particle breakage can reduce the strength of the force-chain, resulting in that the larger particles in the force-chain will be broken slightly or not.