A peridynamics-SPH coupling approach to simulate soil fragmentation induced by shock waves

In this work, a nonlocal peridynamics-smoothed particle hydrodynamics (SPH) coupling formulation has been developed and implemented to simulate soil fragmentation induced by buried explosions. A peridynamics-SPH coupling strategy has been developed to model the soil-explosive gas interaction by assigning the soil as peridynamic particles and the explosive gas as SPH particles. Artificial viscosity and ghost particle enrichment techniques are utilized in the simulation to improve computational accuracy. A Monaghan type of artificial viscosity function is incorporated into both the peridynamics and SPH formulations in order to eliminate numerical instabilities caused by the shock wave propagation. Moreover, a virtual or ghost particle method is introduced to improve the accuracy of peridynamics approximation at the boundary. Three numerical simulations have been carried out based on the proposed peridynamics-SPH theory: (1) a 2D explosive gas expansion using SPH, (2) a 2D peridynamics-SPH coupling example, and (3) an example of soil fragmentation in a 3D soil block due to shock wave expansion. The simulation results reveal that the peridynamics-SPH coupling method can successfully simulate soil fragmentation generated by the shock wave due to buried explosion.