A coupled and parallel peridynamics–SPH modeling and simulation of buried explosion induced soil fragmentation and cratering

In this work, we develop a coupled peridynamics (PD) and smoothed particle hydrodynamics (SPH) model for simulating soil fragmentation, ejection, and cratering under buried explosions. Specifically, the non-ordinary state-based PD theory describes the dynamic response of soil, while the SPH method governs the motion of the explosive gas products. A stable and efficient coupling algorithm for data transfer between PD and SPH is adopted. To accurately capture soil behaviors under blast loading, we propose a modified Drucker–Prager plasticity model incorporating an additional high-pressure compaction equation of state (EoS). Additionally, a parallel code using the OpenMP algorithm is developed for the coupled PD–SPH model to handle large-scale, long-duration soil explosions. PD–SPH predictions are compared with two sets of well-designed centrifugal model tests. The gravitational effect is considered in the simulation to replicate the true physical process of buried explosions in soil. It is found that the coupled PD–SPH model successfully captures the entire physical process of soil fragmentation, ejection, and cratering induced by buried explosions. The predicted soil ejection and cratering morphologies, as well as quantitative results such as ejection speed, ejection height, and crater diameter, align well with the test results. Furthermore, the results indicate that the gravitational effect significantly influences the soil ejection and cratering processes. With increased gravitational acceleration, the soil ejection height and crater size decrease markedly.