Simulation Of Lightning Protection Performance Of Carbon Nanopaper Composites

Lightning is a common weather environment for aircraft,and lightning damage is one of the causes of aircraft failure.Lightning can reduce the strength of the airframe,or even cause breakage and damage,which will cause serious hidden danger to flight safety.With the development of lightweight aircraft design,the application proportion of composite materials in the body structure has been increasing year by year.For example,the proportion of composite materials in the A350 XWB aircraft is as high as 52%.However,the electrical conductivity of resin matrix composites is generally very low.Compared with traditional metal fuselage,resin matrix composites are more likely to suffer severe lightning damage in lightning environment.Therefore,it is necessary to improve the electrical conductivity of the structure in order to realize the improvement of the lightning damage protection performance of the composite materials for the body.In this paper,the electro-thermal coupling finite element model of CFRP composite material is established to discuss the lightning damage results caused by simplified current D waveform.Based on this,the effects of current peak value,current radius,superposition waveform and electro-thermal physical properties of CFRP composites on the lightning damage morphology of CFRP composites were discussed,and the influence mechanism of each factor was qualitatively described.Secondly,the conventional carbon nanopaper is prepared through the steps of stirring,dispersing,suction filtration and drying.On the basis of obtaining the carbon nanopaper,the silver modified carbon nanopaper is obtained after the silver nitrate solution is fully permeated and dried by the ultraviolet lamp.The epoxy resin of the two types of carbon nanopaper is prepared into prepregs,and composite materials are prepared by hot pressing.The thermal stability,electrical conductivity,specific heat,thermal conductivity and other electro-thermal physical properties of the obtained two types of carbon nanopapers and corresponding composite materials were tested and analyzed at room temperature and elevated temperature.Combining with the law of CFRP composite material performance changing with temperature,the material properties of carbon nanopaper composite material changing with temperature are given.Based on this,a finite element model using carbon nanopaper composite as lightning protection layer was established,and the calculated results were compared with the damage of unprotected CFRP composite material to determine the role of carbon nanopaper composite as lightning protection layer.Carbon nano paper is used as a thin-film lightning protection material.In order to improve its lightning protection effect,the influence of its thickness and electrical conductivity is further considered.In this paper,carbon nanopaper composites and CFRP composites are taken as the research objects,and the lightning strike process described by simplified D waveform is simulated to obtain the effect of protective layer on the lightning strike damage results of CFRP composites.The results show that the composite material structure based on carbon nanopaper studied in this paper has a good protective effect on the lightning strike process,and the preparation process is easy to realize,and the obtained material is light in weight and easy to modify.Carbon nanopaper composites show great application potential as lightning protection materials for airframes.