Effect of Clearance Position of Torque Link Structure on Nose Landing Gear Shimmy

The clearance of the torque link will affect the stability of landing gear shimmy. In this paper, a six-degree-of-freedom mathematical model of dual-wheel nose landing gear shimmy including longitudinal bending and axial displacement of the strut is established. The shimmy characteristics of five different positions of clearance at the central connecting pin of the lower torque link and connection between the lower torque link and the inner cylinder of the strut are analyzed by bifurcation diagram, limit cycle and time history diagram. The results show that: there is a clearance on both sides of the head of the lower torque link, compared with the clearance exists only on one side (left or right), the range of the torsional shimmy of the nose landing gear is larger; when there is a clearance on one side (left or right) near 2 mm at the connection between the lower torque link and the inner cylinder of the strut, the torsional shimmy appears a period doubling phenomenon.