The vehicle/track interaction is calculated in the time domain in order to be able t account directly for effects such as the discrete sleeper spacing.
The two first pinned pinned frequencies are situated approximately at 950 and 2200 Hz (UIC60-rail and sleeper spacing of 0.60 m).
The effects of the main influencing parameters including sleeper spacing, rail bending modulus, track stiffness, train speed, and wheel load on the amount of rail seat loads were investigated.
In this approach, the track is represented by an infinitely long periodic structure with the period equal to the sleeper spacing and the vertical irregular profile (roughness) of the railhead is assumed to be periodic in the track direction with the period equal to the length of a number (integer), N, of sleeper bays.
The period of the structure may become greater than the sleeper spacing.
When the damper is not short compared to the sleeper spacing, bending of the beam in a damper may play a role.
For a track with sleepers, a major track type used worldwide, it is normally modeled to be a periodic structure consisting of an infinitely long uniform main structure (i.e., the rails) attached at a given spacing (i.e., the sleeper spacing) by an infinite number of supports (i.e., the railpad/sleeper/ballast).
With the addition of the rail dampers, the period of the track structure is still equal to the sleeper spacing, but within each period, there are two supports, one being the railpad/sleeper/ballast system and the other being two rail dampers.
It is assumed that the track structure is periodic in the x-direction with period equal to L, where L may be equal to, or greater than, the sleeper spacing L 0. In other words, at every length L in the x-direction, the track repeats all the details found in the interval [0, L], which is termed the 0th bay.
Description: A derailed wheel is influenced by high vertical acceleration impulses due to the alternation of sleepers and spaces between the sleepers.
