NUMERICAL SIMULATION OF RIFLE BULLET PENETRATION INTO HOLLOW CONCRETE BLOCKS USING A FAILED NODE-TO-SPH ALGORITHM

In order to reveal the motion law of rifle projectile penetration into hollow blocks, the failure-node-to-SPH (Smoothed Particle Hydrodynamics) algorithm was applied to numerically simulate the process of rifle projectile penetration into the block. High-speed photography was used in experiments to obtain data on the projectile's impact velocity, residual velocity, post-impact motion attitude, and damage to the target. By comparing with experimental data and typical physical phenomena, the numerical method was able to reproduce the projectile's behavior within the block. The results indicate that the failurenode- to-SPH algorithm effectively demonstrates the block fragmentation and scattering phenomenon, with the exit damage pattern almost identical to the experimental results. Furthermore, the projectile penetration process can be viewed as the penetration of a twolayer concrete target with a thin spaced target plate. The number of velocity changes and the peak overload values correspond to the equivalent number of layers. The deflection of the projectile upon exiting the target mainly arises from the attack angle generated before the projectile penetrates the second layer of the target. The residual velocity and overload values are positively correlated with the impact velocity, while the deflection amplitude at the moment of exit is negatively correlated with the impact velocity. The research findings provide a basis for enhancing the capability of small arms to penetrate brick-wall-protected personnel targets.