Smoothed particle hydrodynamics modeling of linear shaped charge with jet formation and penetration effects

Shaped charge, as a frequently used form of explosive charge for military and industrial applications, can produce powerful metal jet and lead to stronger penetration effects onto targets than normal charges. After the explosion of high explosive (HE) charge, the detonation produced explosive gas can exert tremendous pressure on surrounding metal case and liner with very large deformation and even quick phase-transition. In this paper, the entire process of HE detonation and explosion, explosion-driven metal deformation and jet formation as well as the penetrating effects is modeled using a smoothed particle hydrodynamics (SPH) method. SPH is a Lagrangian, meshfree particle method, and has been widely applied to different areas in engineering and science. A modified scheme for approximating kernel gradient (kernel gradient correction, or KGC) has been used in the SPH simulation to achieve better accuracy and stability. The modified SPH method is first validated with the simulation of a benchmark problem of a TNT slab detonation, which shows accurate pressure profiles. It is then applied to simulating two different computational models of shaped-charge jet with or without charge cases. It is found that for these two models there is no significant discrepancy for the length and velocity of the jet, while the shapes of the jet tip are different. The modified SPH method is also used to investigate the penetrating effects on a steel target plate induced by a linear shaped charge jet. The effectiveness of the SPH model is demonstrated by the good agreement of the computational results with experimental observations and the good energy conservation during the entire process.