A PARAMETRIC STUDY OF AIRCRAFT LANDING-IMPACT, WITH EMPHASIS ON NOSE GEAR LANDING CONDITIONS

摘要

A parametric approach to simulation of landingrnimpact, with pitching and heaving degrees ofrnfreedom of the aircraft motion, has been used torndetermine the response of the main and noserngears. Compared to each gear's independentrnbehavior, there are important differences in thernlanding conditions and in the resulting verticalrnloads and displacements when these aircraftrnmotions are included. For main gears, thernmaximum vertical loads are almost linearlyrndependent on the sinking speed but there is somernvariation in the proportion of kinetic energyrnabsorbed. For nose gears no similarity validityrnexists with single gear results. Correlation withrnaircraft sinking speed is absent and the responsernis sensitive to the values of initial pitch anglernand pitch inertia. This is due to the equivalentrnmass at this location being greatly affected byrnthese input quantities and by the aircraft scale.