Ballistic response of sandwich shell panels: A comparative study

The present work was carried out to explore the impact response of hemispherical (HSS), cylindrical (CSS) and flat sandwich structures (FSS) subjected to high-velocity impact through experimental and numerical simula-tions. All three-sandwich structures comprised of Al 1100-H12 face skins and Al-3003 H12 honeycomb core. For the direct comparison, the radius and thickness of all three-sandwich structures were kept identical. The high velocity impact tests were performed by using a pneumatic air gun. The hemispherical and conical shape pro-jectiles were impacted typically at the centre (axis) of the sandwich structures with varying impact velocity. The finite element simulations were carried out through commercially available software Abaqus/explicit. The numerically obtained test results were validated through the experimental results to check the accuracy of the modelling. The response of all three structures was examined by comparing their ballistic resistance, failure mechanics and energy absorption characteristics. In addition, the parametric study was conducted numerically by changing the face skin thickness, cell length and cell wall thickness to find out their influence on the impact response of all three structures. The results revealed that the hemispherical structures showed higher impact resistance in terms of higher ballistic limit velocity and energy absorption. The ballistic limit of the HSS structure was 14.6% and 36.5% higher than the CSS and FSS structure respectively against hemispherical nosed projectile whereas the corresponding value against conical projectile was 9.9% and 20.6% respectively.