Studying Normal and Oblique Perforation of Steel Plates with SPH Simulations

摘要

Axisymmetric and three-dimensional smoothed particle hydrodynamics (SPH) models are developed to simulate normal and oblique perforation of 12 mm-thick Weldox 460 E steel plates. In the models, a particle-to-particle contact algorithm including friction effect is employed to model interactions between projectile and target plate. A constitutive model coupling viscoplasticity and ductile damage is implemented to describe material behaviors of target plate. Both axisymmetric and three-dimensional SPH models are validated by existing experimental results. By using axisymmetric models, effects of projectile structure on normal perforation are systematically studied. Two factors of projectile structure, nose shape and aspect ratio, are considered. Residual velocities, ballistic limits and failure modes are obtained for different projectile nose shapes and aspect ratios. Effects of nose shape and aspect ratio on ballistic limits predicted by SPH simulations are compared with those obtained by an analytical equation. By using three-dimensional models, oblique perforation is simulated. Effects of oblique angle on impact processes are analyzed. Intervals of critical oblique angle of ricochet are obtained for different impact velocities and caliber-radius-head values of ogival projectile. The results obtained in this work can provide reference for the design of protective structures with steels and similar materials. The SPH with contact algorithm including friction effect is proved to be a very effective method for ballistic impact simulation.