The Shimmy Vibration Analysis of Aircraft Landing Gear

shimmy vibration is one of the main important problems encounters in the design of aircraft landing gear and maybe occur in the ground maneuver, take-off and landing operations. The elasticity of landing gear mechanism and the tire’s flexibility are the principal source of this phenomenon. In this paper, the shimmy vibration of landing gear is investigated within the framework of linear and nonlinear model. The landing gear is considered with non-zero rake angle which is incorporated into the effective caster length and the classical stretched string theory is used for the simulation of tire mechanical behavior. Then, the governing equation of motion is derived and the linear and nonlinear dynamical behavior is studied. The linear stability analysis is performed and the nonlinear behavior of the system is accomplished thorough time history response and compared with linear results. It is demonstrated that the nonlinear analysis anticipate the limit cycle of the landing gear which is known as shimmy vibration.