Study On Optimization Design Technology For Landing Gear Shock-absorbing System Of Large Civil Aircraft

Under the background of aircraft post landing gears, air-spring force formula has been derived based on traditional two-mass model, by considering oil incompressible and compressible. Furthermore, an empirical formula about friction coefficient which is determined by the parameters of aircraft motion, tire geometry and runway has been established to obtain ground horizontal reaction force.Taking Y8 main landing gear as an example, drop virtual prototyping based on ADAMS/Aircraft has been achieved, and drop simulation has been conducted. There is a good corespondence between the simulation result and the experimental data.The optimization model of variable-orifice is expressed. That is, the metering pin area of section is the design variable. Combined with Adams/Aircraft, the multi-objective optimization of landing gear shock-absorbing system is established in iSIGHT. Under use work drop case, shock strut axial force decreases about 7%, and shock strut effectiveness can increase 6% more at the same time after optimization.Based on conventional design methods, the design optimization of nose and main landing gears of large civil aircraft capability is preceded integrated by the procedure above. As a result, the shock strut efficiency of nose landing gear is improved 19.6%. However, the strut axis force is reduced 15.9%. In corresponds, the shock strut efficiency of main landing gear is enhanced 8.7%.However, the strut axis force is lessened 7.2%. The shock-absorbing characteristics of nose and main landing gears are significantly evaluated.