3D radar stealth composite hierarchical grid structure with extremely broadband absorption performance and effective load bearing

Multifunctional structures with both excellent microwave absorption performance and mechanical properties have attracted great attentions recently due to wide applications in aircraft and ships. In this research, a novel absorption structure was designed and fabricated through molding and interlocking technology by perfectly combining the composite hierarchical grid structure with excellent mechanical properties and extremely broadband 3D absorption metamaterial. The mechanism of structural parameters affecting absorption and mechanical properties of the proposed 3D radar absorption composite hierarchical grid structure (3D-RACHGS) were investigated. The measured result of reflectivity showed that −10 dB absorption bandwidth of 3D-RACHGS achieves 34.8 GHz (2.6–4 GHz, 6.6–40 GHz) with an average reflectivity of −17.4 dB. Further simulation demonstrated that the broadband absorption is attributed to multiple stationary wave modes. The measurement result of out-of-plane compression showed that the specific strength of the 3D-RACHGS achieves 123.5 × 103 m2/s2, which proves its effective load bearing. Failure mechanism map was also constructed to predict the failure mode of the 3D-RACHGS with various structural parameters. The proposed 3D-RACHGS will contribute to the vigorous development of the novel structural absorption materials and have immense potential to be used in new generation multifunctional skin and inlet.