Fem study on the penetration of projectiles into steel sheets

The impact resistance and the fracture behaviour of sheet metals under ballistic impact conditions which depend significantly on some material characteristics like cold work hardening and ductility are important for the development of passive protection systems for passenger cars. To establish the impact of a projectile during penetration of a sheet metal, a FEM model was generated using the commercial FEM-code Abaqus/Explicit. The model was evaluated with real shooting experiments, where the impact behaviour of sheets made of different steels was tested at a shooting stand and the penetration was analysed metallographically. The evaluation showed that reasonable results from the simulation can only be achieved using a damage model concept and when the deformation of the bullet is considered in interaction with the deformation of the sheet metal. The variation of sheet thickness in the simulation shows good agreement with empirically developed formulations to predict the penetration power of a full metal jacket in steel sheets. With the evaluated model, parameter studies were performed to investigate the energy loss during the impact of a projectile into steel sheets with different hardening rates. The studies show that FEM simulation can give good basic knowledge about the impact behaviour of a projectile into steel sheets and can help to achieve higher protection in conjunction with weight reduction in protected passenger cars.