There is an urgent need for the application of broadband Microwave Absorption(MA)structures on the leading edges of aircraft wings,which requires the MA structures to possess both the broadband MA performance and grea...There is an urgent need for the application of broadband Microwave Absorption(MA)structures on the leading edges of aircraft wings,which requires the MA structures to possess both the broadband MA performance and great surface conformability.To meet these requirements,we designed and fabricated a flexible bioinspired meta-structure with ultra-broadband MA,thin thickness and excellent surface conformality.The carbonyl iron powder-carbon nanotubes-polydimethylsiloxane composite was synthesized by physical blending method for fabricating the MA meta-structure.Through geometry-electromagnetic optimal design by heuristic optimization algorithm,the meta-structure mimicking to the nipple photonic nanostructures on the eyes of moth can achieve ultra-broadband MA performance of 35.14 GHz MA bandwidth(reflection loss≤–10 dB),covering 4.86–40.00 GHz,with thickness of only 4.3 mm.Through simple fabrication processes,the meta-structure has been successfully fabricated and bonded on wings’leading edges,exhibiting excellent surface conformability.Furthermore,the designed flexible MA meta-structure possesses significant Radar Cross-Section(RCS)reduction capability,as demonstrated by the RCS analysis of an unmanned aerial vehicle.This flexible ultra-broadband MA meta-structure provides an outstanding candidate to meet the radar stealth requirement of variable curvature structures on aircraft.展开更多
Electromagnetic sandwich metastructure(ESM)consisting of different functional layers,has gained in-creasing attention in radiation prevention and radar stealth.However,the current ESM design is primar-ily based on the...Electromagnetic sandwich metastructure(ESM)consisting of different functional layers,has gained in-creasing attention in radiation prevention and radar stealth.However,the current ESM design is primar-ily based on the separation design method,ignoring electromagnetic-mechanical interactions between layers.Thus,subject to thin thickness constraint of ESM,it is a great challenge to achieve broadband microwave absorption(MA)and excellent mechanical performance simultaneously.To address this is-sue,an electromagnetic-mechanical collaborative design approach was proposed for ESM.The relations of geometric-electromagnetic and geometric-mechanical of ESM were first identified by machine learn-ing.They were then integrated with the heuristic genetic optimization algorithm to perform the highly efficient design.The designed ESM can achieve 36.4 GHz effective absorption bandwidth(EAB,RL≤-10 dB),334.3 MPa equivalent bending strength and 83 MPa compressive strength with a thickness of 9.3 mm,possessing the widest EAB and highest bending strength within the current available MA struc-tures(thickness less than 9.5 mm).The proposed approach provides an efficient tool for the design of electromagnetic-mechanical optimal ESM.展开更多
基金supported by the Basic Research Development Program of China(No.JCKY2021607B036)the National Natural Science Foundation of China(No.52275512).
文摘There is an urgent need for the application of broadband Microwave Absorption(MA)structures on the leading edges of aircraft wings,which requires the MA structures to possess both the broadband MA performance and great surface conformability.To meet these requirements,we designed and fabricated a flexible bioinspired meta-structure with ultra-broadband MA,thin thickness and excellent surface conformality.The carbonyl iron powder-carbon nanotubes-polydimethylsiloxane composite was synthesized by physical blending method for fabricating the MA meta-structure.Through geometry-electromagnetic optimal design by heuristic optimization algorithm,the meta-structure mimicking to the nipple photonic nanostructures on the eyes of moth can achieve ultra-broadband MA performance of 35.14 GHz MA bandwidth(reflection loss≤–10 dB),covering 4.86–40.00 GHz,with thickness of only 4.3 mm.Through simple fabrication processes,the meta-structure has been successfully fabricated and bonded on wings’leading edges,exhibiting excellent surface conformability.Furthermore,the designed flexible MA meta-structure possesses significant Radar Cross-Section(RCS)reduction capability,as demonstrated by the RCS analysis of an unmanned aerial vehicle.This flexible ultra-broadband MA meta-structure provides an outstanding candidate to meet the radar stealth requirement of variable curvature structures on aircraft.
基金supported by the National Natural Sci-ence Foundation of China(Nos.52375383 and 52035011).
文摘Electromagnetic sandwich metastructure(ESM)consisting of different functional layers,has gained in-creasing attention in radiation prevention and radar stealth.However,the current ESM design is primar-ily based on the separation design method,ignoring electromagnetic-mechanical interactions between layers.Thus,subject to thin thickness constraint of ESM,it is a great challenge to achieve broadband microwave absorption(MA)and excellent mechanical performance simultaneously.To address this is-sue,an electromagnetic-mechanical collaborative design approach was proposed for ESM.The relations of geometric-electromagnetic and geometric-mechanical of ESM were first identified by machine learn-ing.They were then integrated with the heuristic genetic optimization algorithm to perform the highly efficient design.The designed ESM can achieve 36.4 GHz effective absorption bandwidth(EAB,RL≤-10 dB),334.3 MPa equivalent bending strength and 83 MPa compressive strength with a thickness of 9.3 mm,possessing the widest EAB and highest bending strength within the current available MA struc-tures(thickness less than 9.5 mm).The proposed approach provides an efficient tool for the design of electromagnetic-mechanical optimal ESM.
