In this investigation, dynamic characteristics of independently rotating wheel systems (IRW) are discussed. To this end, a multibody IRW model is developed using the method of velocity transformation. The linear stability analysis of a two-axle IRW truck is first performed, and the hunting stability and vibration characteristics of IRW truck are investigated and the results are compared with those obtained using the multibody dynamics model. Good agreements are obtained in hunting frequencies and critical speed. It is shown using the linear IRW equations that since a constant forward speed is assumed for IRW, the longitudinal slip can occurs due to the change in the wheel rolling radii resulting from the lateral displacement. This leads to longitudinal creep forces even in the case of IRW and it contributes to a weak coupling of the lateral and yaw motion of IRW. Furthermore, it is observed in several numerical examples that, due to small self-centering forces of IRW, continuous flange contact occurs on tangent track, while in curve negotiation flange contacts on outer wheel of the front axle as well as that on inner wheel of the rear axle occurs. It is presented that the received wisdom that longitudinal creep forces of IRW ideally equal to zero is contradicted in tight curve negotiation and special care need to be exercised when a simplified IRW model is used.

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