Tore Dahlberg - Solid Mechanics/IEI, Linkoping University, SE-۵۸۱ ۸۳ Linkoping, Sweden

The track stiffness experienced by a train will vary along the track. Sometimes the stiffness variation may be very large within a short distance. One example is when an unsupported sleeper is hanging in the rail. Track stiffness is then, locally at that sleeper, very low. At insulated joints the bending stiffness of the rail has a discontinuity implying a discontinuity also of the track stiffness. A third example of an abrupt change of track stiffness is the transition from an embankment to a bridge. At switches both mass and stiffness change rapidly.

Under-sleeper pads, track stiffness variations, wheel/rail contact force, ballast protection