Study on Energy Absorption of Water-Filled Multi-Layered Panels Subjected to High-Velocity Perforating Impacts

The mutual effect of projectile length and fluid core thickness in fluid-filled sandwich structures in terms of kinetic energy absorption has not been studied extensively in the literature. This research investigates the energy absorption of three-layered targets in which a water layer is confined between two steel plates and subjected to high-velocity impacts using experimental and numerical methods. In the primary experimental part of the study, three sets of specimens were fabricated with different core thicknesses (20, 30 and 40[Formula: see text]mm) to examine the influence of fluid-core thickness. The front and back skins were fabricated from DIN 1623 steel plates with one mm of thickness. Blunt-headed cylindrical steel projectiles weighing 5.5[Formula: see text]grams were fired using a gas gun, with an average input velocity of 220[Formula: see text]m/s. The entering and residual velocities of the projectile were measured using light sensors. The experimental results revealed that there is no monotonic relation between core thickness and residual velocity, and the maximum decrease in projectile velocity occurred at a fluid core thickness of 30[Formula: see text]mm. The extended experiments and numerical simulations with longer projectiles demonstrated that the projectile length could play a considerable role in the migration of the magnitude of fluid thickness corresponding to maximum energy absorption. In the extended studies within the studied parameter range, it was found that the optimum fluid thickness falls in the range of approximately twice as long as the projectile length.