Abstract：To reveal the influence law of the clearance at the connection between nose landing gear and airframe on shimmy stability, a six-degree-of-freedom shimmy dynamic model with such clearance was established. The clearance was converted into strut rotation angle via geometric mapping, and the nonlinear stiffness torque equation was smoothed. The influence of the clearance on shimmy stability was analyzed based on bifurcation theory. The results show that considering airframe local stiffness significantly affects the shimmy region; the torsional shimmy region expands as equivalent stiffness decreases, while the lateral shimmy region shows an opposite trend with equivalent stiffness variation; with increasing clearance, the torsional shimmy region shrinks and the lateral one expands; at a fixed taxiing speed, 0.1-0.2mm clearance can effectively suppress shimmy amplitude.
2026, Vol. 47 
