Numerical study on the blocking effect of skin on Flash-Ball Impact and damage assessment

To explore the response law of non-lethal large-size kinetic energy projectiles to blunt attack on skin tissue, and to evaluate the skin injury characteristics of the attacked personnel and the use safety of kinetic energy projectiles. Based on the LS-DYNA simulation software, a three-layer skin simulation model and a Flash-Ball rubber bullet model are established, and the force-time and deformation-time biomechanical corridors of the Flash-Ball rubber bullet impacting human skin tissue are obtained. The corridor curve and the energy transfer and diffusion are analyzed and compared. The safety evaluation of the damage caused by the rubber bullet shooting a human body at different distances is carried out using the empirical formula of the penetration limit. Finally, the safe shooting distance is obtained. The results show that the model used in the simulation has a good correlation with the experimental data, its biomechanical corridor characteristics are different from those of conventional vehicle impact and small-size projectile response characteristics. The energy transfer and action time of medium and low-speed impact may cause greater damage. The fat layer is the largest energy absorption unit. The minimum safe shooting distance to ensure skin tissue from penetrating damage is 15.8 m, and the limit specific kinetic energy of skin damage is 7.88 J/cm2. This study can be extended to the study of biomechanical response law and safety evaluation under the impact of the same type of large kinetic energy projectile, which provides an important theoretical reference for the police to use large kinetic energy projectiles to conduct safe shooting in peacekeeping operations.