Bifurcation Analysis of a Coupled Nose Landing Gear-Fuselage System

Under certain conditions during takeoff and landing, pilots may sometimes experience vibrations in the cockpit. Because the cockpit is located right above the nose landing gear, which is known to potentially be prone to self-excited vibrations at certain velocities, an explanation for those vibrations might be oscillations of the landing gear feeding into the fuselage. However, the fuselage dynamics itself may also influence the dynamics of the landing gear, meaning that the coupling must be considered as bidirectional. A mathematical model is developed to study a coupled nose-landing-gear–fuselage system, which allows to assess the overall influence of the coupling on the system dynamics. Bifurcation analysis reveals that this interaction may be significant in both directions and that the system behavior depends strongly on the modal characteristics of the fuselage.