The Motion of a Railway Wheelset on a Track or on a Roller Rig

The kinematic motion of a wheelset of a railway vehicle rolling on a pair of rails without slips is studied. The exact linearized motions for a wheelset on a tangent track and for a wheelset on a roller rig are derived. Furthermore, equations for the symmetric case for finite amplitudes are presented, which show that the wavelength of the kinematic motion depends on the amplitude. From a dynamic analysis, it is shown how the critical speed of a real wheelset with tyre slips and suspension stiffness relates to the kinematic motion.