Numerical Investigation on the Failure Behavior of Brittle Granular Chain under Impact

Abstract

In brittle granular materials, the fragmentation waves have received far less attention due to their complexity despite of their significant role in mineral processes, earthquake hazards control, etc. In this research, the Material Point Method (MPM) is used to analyze how fragmentation waves propagate in a 3-dimensional 10 brittle beads chain with a rate-dependent elasto-damage model. The simulations show that generally, the second bead will become the most severely damaged one, followed by the third bead. Most failure points will appear near the contact surface between the brittle spheres and extend to interior conically. An interesting phenomenon is that with a lower damage threshold or fracture energy, despite of the increase of total damage in the whole chain, less damage is developed in some beads after a period of time. This is mainly because more damage in the beginning dissipates excessive stress wave energy to the extent such that the reflected wave will not be able to cause more damage in the local system.