Influences of thickness and stacking sequence on ballistic impact behaviors of GLARE 5 FML plates: Part II – Numerical studies

This two-part article examines the effects of thickness and stacking sequence of GLARE 5 (2024-T3 aluminum alloy-unidirectional S2-glass/epoxy) fiber–metal laminated (FML) plates subjected to ballistic impact. Part I presented experimental observations of damage development in the specimens, C-scan damage contours, projectile velocity profiles and ballistic limit velocities (V₅₀). Part II concerns with finite element (FE) modeling of the FML plates. The 3D FE code, LS-DYNA, was used to model and validate the experimental results. Experimentally obtained incident projectile impact velocity versus the residual velocity (V_i∼V_r), damage patterns and bullet residual length were used to validate the FE model. Good agreement was achieved between experimental and numerical results. It was found that for a given specimen thickness/stacking-sequence, by increasing the projectile incident velocity up to its V₅₀ value, the maximum contact force increased. By further increasing the projectile velocity above its V₅₀, the maximum contact force was relatively invariant with respect to an increase in the projectile incident velocity.