Multiple ballistic impacts of thin metallic plates: Numerical simulation

The ballistic performance of protective structures under multiple projectile impacts attracts increasing attention due to its practical importance, and existing studies were seldomly devoted to exploring how the structure would deform and fail when subjected to such loads. This study aimed to characterize the multi-hit ballistic resistance of fully-clamped thin plates made of 304 stainless steel using finite element method, with the equivalent plastic strain employed to define material damage and failure/fracture. The numerical model was validated against existing experimental results of double impacts at the same location, with good agreement achieved. The model was subsequently employed to quantify the effects of impact position, interval time between successive hits, projectile nose shape (e.g., spherical, flat, and conical), and boundary condition of target plate on ballistic limit and deformation/failure modes. Further, ballistic limit boundaries were constructed for both double and triple impacts of projectiles. Obtained results are helpful for designing high-performance protective structures against multiple projectile impacts.