大型客机起落架缓冲系统优化设计技术研究

大型客机起落架缓冲系统优化设计技术研究ABSTRACTUnder the background of aircraft post landing gears,air-spring force formula has been derivedbased on traditional two-mass model,by considering oil incompressible and compressible.Furthermore,an empirical formula about friction coefficient which is determined by the parameters ofaircraft motion,tire geometry and runway has been established to obtain ground horizontal reactionforce.Taking Y8 main landing gear as an example,drop virtual prototyping based on ADAMS/Aircrafthas been achieved,and drop simulation has been conducted.There is a good corespondence betweenthe simulation result and the experimental data.The optimization model of variable-orifice is expressed.That is,the metering pin area of sectionis the design variable.Combined with Adams/Aircraft,the multi-objective optimization of landinggear shock-absorbing system is established in iSIGHT.Under use work drop case,shock strut axialforce decreases about 7%,and shock strut effectiveness can increase 6%more at the same time afteroptimization.Based on conventional design methods,the design optimization of nose and main landing gearsof large civil aircraft capability is preceded integrated by the procedure above.As a result,the shockstrut efficiency of nose landing gear is improved 19.6%.However,the strut axis force is reduced15.9%.In corresponds,the shock strut efficiency of main landing gear is enhanced 8.7%.However,thestrut axis force is lessened 7.2%.The shock-absorbing characteristics of nose and main landing gearsare significantly evaluated.Keywords landing gear,ADAMS,virtual prototyping,metering pin,iSIGHT,multi-objectiveoptimization