Experiments on Quasi-Periodic Wheel Shimmy

The lateral vibration of towed wheels — so-called shimmy — is one of the most exciting phenomena of vehicle dynamics. We give a brief description of a low degree of freedom rig of elastic tyre that was constructed for laboratory measurements. A full report is given on the experimental investigation of this rig from the identification of system parameters to the validation of stability boundaries and vibration frequencies of shimmy motion. The experimental results confirm the validity of those tyre models that include delay effects. A peculiar quasi-periodic oscillation detected during the experiments is explained by numerical simulations of the nonlinear time-delayed mathematical model.