Airworthiness Analysis And Numerical Simulation Of Bird Impact On Large Civil Aircraft Windshield

Bird strikes are always serious threats to airviation safty.While the development of air transportation industy is rapid,the problem of bird strike has not been improved.The increase of the flight and f light speed makes bird strike problem more and more unignorable.Accroding to the US wildlife strike database,the number of aircraft windshield against bird strike is 16% of the total,ranking the first.So,it is necessary to put more attention on the study of windshield against bird strike.At present,multilayer windshields are more and more applied to the large civil aircraft.Compared with the single layer windshields,multilayer windshield can absorb more energy,and has better stability,strength and stiffness under the same weight.However,the research of multilayer windshields against bird strike is relatively few and is mainly focused on the sandwich plate.As a result,this paper carried out dynamic response analysis of large civil aircraft multilayer windshield against bird strike,in hope to provide some reference for airworthiness certification and design of large civil aircraft multilayer windshield against bird strike.This paper firstly summarized the history of development of bird strike airworthiness regulations in European and Amer ican and the controversy of bird weight in the airworthiness regulations,deeply analyzed the bird strike airworthiness regulation of transport aircraft in our country,discussed the compliance verification method of bird strike,in order to provide airworthiness regulations basis for the bird strike problems.Secondly,this paper analyzed var ious factors related to the numerical anslysis of bird strike,including the geometric model,constitutive model,element type for the bird and windshield,boundary condition of windshield,impact angle,impact locations,impact velosity etc.Based on the bird strike airworthiness regulations and basic factors of numerical analysis,this paper formed the CATI A-ANS YS-DYNA joint numerical analysis system.In order to verify the feasibility of the system,it compared the numerical results with the exisiting exper iment results.Finaly,it established the numerical analysis model of large civil aircraft multilayer windshield against bird strike,simulated the process of bird impacting the windshield,analyzed the stress condition and failure mode of multilayer windshield after bird strike.