Numerical simulation of shock wave propagation in dry sand based on a 3D mesoscopic model

Mesoscopic modelling has been an effective approach in predicting the averaged dynamic states of dry sand under intense dynamic events, such as impact, blast and penetration. Many previous studies are limited to two-dimensional (2D) formulations due to computational cost. This paper develops a three-dimensional (3D) mesoscopic model of dry sand particulate system to get insight into a shock wave propagation under blast. The sand particle is modelled using a polyhedron with a random shape. The deformation, elastic or permanent deformation, of single particle is considered in simulation. It resolves explicitly the particle to particle contact and friction effects based on the mesoscopic model. In simulation, averaging is used to perform a macroscale analysis of the quantities and the distributions on shock variables. It simulates the shock wave propagation and the attenuation effects of dry sand particles on the peak pressure of the transmitted shock wave. The wave propagation in the dry sand is calculated and discussed numerically. The dependence of peak pressure and propagation velocity on the incident shock is presented. The variations in the dry sand configurations and the correlations to pressure are as well as discussed under shock events. Mesoscopic observation reveals that the permanent deformation and contact and friction effects are the origin of energy absorption capability. It leads to the attenuation on the shock wave.