Development of mortar filled honeycomb sandwich panels for resistance against repeated ballistic impacts

Growing security threats demand structures offering exceptional energy absorption and heat dissipation capabilities with minimum damage. Sandwich structures are adopted widely for resisting ballistic impacts. Honeycombs filled with composites propose significant resistance by energy absorption or heat dissipation due to localized encapsulated damage. Therefore, this research focuses on developing composite sandwich panels that can resist multiple ballistic impacts to a considerable degree. It constituted a core of Aluminum Honey Combs (AHC) Al3003 and Al5052 filled with cement mortar containing tire rubber dust (15%), iron powder (20%), glass powder (25%), and polyvinyl (PVA) fibers (1.5%) and wrapped with C-230 Carbon Fiber Reinforced Polymers (CFRP). These panels experimented with CEN 1063 standard in a controlled testing environment against 19 mm (640 J), 45 mm (1800 J), and 51 mm (3270 J) bullets. All samples resisted ballistic impacts of 19 mm and 45 mm with indentation within 25 mm Back Face Signature (BFS). However, ballistic impacts of 51 mm bullets pierced through and caused only localized damage maintaining structural integrity, compactness, and durability.