Analysis of the influence of the finite elements mesh density on the determined shaped charge jet parameters

Article presents results of numerical analyses of the finite elements mesh density influence on the shaped charge jet stream formation process and its selected parameters. Authors considered classical shaped charge, which consists of the plastic explosive material, copper liner and aluminium case. To properly described, material properties of the liner and case of the shaped charge, the Johnson-Cook material model was used. Detonation process was described using burn model approach. Behaviour of the detonation process products was described by commonly used John-Wilkins-Lee equation of state. Due to the nature of the presented phenomenon, in which we are dealing with large strains and strain rates, for its modelling authors utilized Euler description, implemented in the LS-Dyna software. In these method material flows by the finite elements and mesh is not deformed. Such approach allows for modelling phenomena where large and very large deformations occur. Unfortunately, it can result in a destabilizing of the systems energy balance. In order to minimize dissipation processes, in calculations was used second order scheme because of the spatial variables and time. Analyses were performed in axially symmetric setup, which was possible due to the symmetry of the analysed system. Influence of the finite elements size on the process of jet stream formation and its selected parameters was analysed