Hybrid continuum–discrete simulation of granular impact dynamics

Granular impact -- the dynamic intrusion of solid objects into granular media is widespread across scientific and engineering applications including geotechnics. Existing approaches for simulating dynamics have relied on either a pure discrete method or continuum method. Neither these methods, however, deemed optimal from computational perspective. Here, we introduce hybrid continuum-discrete approach, built coupled material-point discrete-element (MP-DEM), with unparalleled efficiency. To accommodate highly complex solid-granular interactions, enhance existing MP-DEM formulation three new ingredients: (i) robust contact algorithm that couples parts without any interpenetration under extreme loads, (ii) large deformation kinematics employing multiplicative elastoplasticity, (iii) trans-phase constitutive relation capturing gasification media. For validation, also generate experimental data through laboratory measurement spheres dropped onto dry sand. Simulation experiments shows proposed approach can well reproduce in terms forces, depths, splash patterns. Further, parameter studies material properties, model formulations, numerical schemes, identify key factors successful simulation dynamics.