| When aircraft is braking while landing, the landing gear walk phenomenon occurs under certain circumstances such as a rough change of brake torque and some certain brake frequency. Landing gear vibration endangers landing gear mechanism, brings discomfort to passengers and pilots, and even leads directly to catastrophic flight accidents. As a result, landing gear vibration is a key problem to aircraft landing dynamic issues. Research on gear walk has important significance to the design of landing gear and brake system.This paper focuses on a certain type of aircraft, first the brake and taxi model of the aircraft, landing gear model and braking wheel model have been introduced. Then rigid-flexible coupling dynamic model has been established by applying CATIA, Hypermesh and Adams addressing the theoretical model. Afterwards, gear walk concept and its relation with braking has been introduced and analyzed. Moreover, addressing main landing gear, parameters such as brake torque, cohesive force between tire and road, as well as normal displacement of wheel axle during the braking process has been analyzed systematically, thus the relation between brake torque and gear walk has been set up. Anti-skid control strategies including deceleration control and slip rate braking control methods are introduced, two types of anti-skid brake control systems has been constructed. By applying these two control systems, the dynamic model’s braking simulations have been performed, and the results come out. After thorough research and conscientious comparisons, two different gear walk phenomena due to different brake methods, as well as two cases of different performance of anti-skid brake strategies have been concluded. Results indicate that deceleration control method poses inferior to the slip rate braking control method in the field of reducing gear walk phenomenon.A reliable process of analyzing brake-induced gear walk phenomenon has been established, as well as a relatively complete process for further research. A fair amount of meaningful results have been acquired along the way, which offers a creditable reference for researches of brake-induced low frequency vibration and the design of aircraft brake systems. |
