Fretting Fatigue Properties in Rail Steel and Fish Plate Materials. Effects of Contact Pressure and Relative Slip Amplitude.

The fretting fatigue of rail steel with fish plate were examined using the clamping contact double bridge pads system. In order to investigate the effects of contact pressure and relative silp amplitude on fretting fatigue strength, the fretting fatigue tests were carried out at three contact pressures and with three pad lengths. The fretting fatigue strength decreased with increasing contact pressure for all stresses and with increasing pad length at higher stresses. Interrupted fretting fatigue tests were carried out in order to investigate the fretting damage. The ratio of the crack initiation life due to the effect of fretting damage to the whole fatigue life was less than 60%, and the effect was influenced by the relative slip amplitude.