Research On Comprehensive Design Technology Of Electromagnetic/Mechanical Performance Of Radar Absorbing Structure

Absorbing materials refer to a class of important functional materials that can effectively absorb and dissipate the electromagnetic energy,and are widely used in national defense and civil use.The absorbing materials can be generally divided into coating radar absorbing material and structure radar absorbing material.The structure radar absorbing material is a kind of multi-functional material,which can absorb electromagnetic waves,have the capacity of bearing and the bandwidth of absorbing frequencies.The honeycomb core has light weight,high rigidity and strength,and is widely used as a sandwich core of a structure radar absorbing material.At this stage,the research on the mechanical and electromagnetic properties of honeycomb structure absorbing materials is often carried out independently,which limits multifunctional design and application of honeycomb structure.In view of the above problems,this paper mainly takes the aramid paper honeycomb absorbing structure as the research object.The three hexagonal absorbing structures such as the traditional hexagonal honeycomb absorbing structure,the reinforced honeycomb absorbing structure,the auxetic honeycomb absorbing structure are tested and simulated.The connection and matching relationship between the mechanical and electromagnetic properties of the above three structures are explored.This paper proposes design guidance for the multi-functional performance of the honeycomb structure.The main work and innovations of the paper are as follows:(1)A comprehensive investigation on the electromagnetic and mechanical properties of the aramid paper honeycomb absorbing structure is studied.Through the reflectivity experiment and electromagnetic software simulation,we explore the effect of the aperture size and height on the absorption performance of the hexagonal honeycomb wave absorbing structure.Through the compression experiment,we get the mechanical properties such as: flat compression strength,failure mode,flat compression elastic modulus,load-stroke curve.According to the research,we have the following conclusions.As the height of the honeycomb increases,the mechanical and electromagnetic properties of the honeycomb are enhanced.Under a thin coating,honeycomb with 1.83 mm aperture has better absorption performance and poorer mechanical properties than honeycomb with 2.75 mm aperture.With the thickness of the coating increasing,the 2.75 mm large-aperture honeycomb has better absorbing properties and mechanical properties than the 1.83 mm small-aperture honeycomb.(2)In order to obtain excellent mechanical and electromagnetic properties at the same time,we propose a reinforced honeycomb absorbing structure(RHAS),without changing the honeycomb structure unit.Through the reflectivity experiment and compression experiment,the influence of the reinforcement layer on the mechanical and electromagnetic properties is explored,which is between the honeycomb wall and the absorbing coating.The research results show that,keeping the height of the honeycomb unchanged,the mechanical strength of the RHAS is greatly improved compared with the traditional honeycomb absorbing structure.The density of RHAS increase by 296.67%,and the destruction mode of RHAS change.When the thickness of the coating is thin and the height of the RHAS is 23 mm,the absorption of the incident wave energy in the bandwidth of 2-18 GHZ can exceed 90%.(3)The auxetic structure is a bulging structure,which has more excellent mechanical properties than the traditional hexagonal honeycomb structure.In this paper,the electromagnetic performance of the auxetic honeycomb absorbing structure(AHAS)is analyzed and studied.Through CST simulation,it is investigated whether the absorbing performance and mechanical property of the AHAS has the same law of variation of angle and aspect ratio.The research results show that: under a thin coating,the AHAS has better absorbing performance than hexagonal honeycomb absorbing structure;for AHAS,the change law of absorbing performance with angle and aspect ratio are the same as mechanical properties;Compared with the traditional hexagonal honeycomb absorbing structure,the AHAS achieves the same absorbing performance with more lightweight,which means it does not bring a significant increase in weight and density.