Broadband stealth composite metastructure with high penetration protection

Microwave absorption plays an important role in modern electromagnetic protection and compatibility. However, lack of mechanical and impact design restricts their practical applications. Herein, a composite armor (CA) incorporating metastructure design with mixed characteristic periods was optimized by embedded genetic algorithms and inversion framework of equivalent impedance derivation. The −10 dB absorption bandwidth was covered from 2 GHz to 18 GHz. The impact-penetration ballistic experiments and simulation verified the penetration protection of CA against large caliber armor-piercing incendiary (API) with target impact speed of more than 745.1 m/s. The CA fabricated by ultra-high molecular weight polyethylene fiber reinforced polymer (UFRP), carbon fiber reinforced polymer (CFRP) and alumina ceramics showed better penetration protection performance than the counterparts with titanium and aluminum alloys with the same weight. Compared with traditional armor steel with similar protection performance, more than 30% weight is reduced for the proposed composite armor.