Research on influence of tire stiffness characteristics on shimmy of large civil aircraft nose landing gear

Abstract

Tire stiffness is one of the important parameters of tire dynamics model. The influence law of tire stiffness on the shimmy of large civil aircraft nose landing gear can provide reference for the anti-shimmy design of large civil aircraft nose landing gear. The nonlinear mathematical model of the nose landing gear shimmy is established, and the shimmy region diagram of different tire torsional stiffness and tire side bending stiffness is calculated by using Matlab/Matcont software. The influence law of tire torsional stiffness and tire side bending stiffness on the shimmy of the nose landing gear is studied, and the sensitivity of the two on the shimmy of the nose landing gear is compared. The results show that the sensitivity of tire torsional stiffness to the impact of nose landing gear shimmy is greater than that of tire lateral bending stiffness. When the positive torque coefficient is decreased by 1%, the maximum critical damping of torsional shimmy is decreased by 0.88%, and the minimum critical damping of lateral shimmy is increased by 33.87%. Reducing the torsional stiffness of tire and increasing the lateral stiffness of tire are beneficial to restrain the yaw of large civil aircraft nose landing gear.

Keywords

• large civil aircraft
• nose landing gear
• shimmy
• tire stiffness
• nonlinearity
• bifurcation