Likewise, in order to represent the contamination on the rail surface, the Kalker coefficient is reduced to 0.8.
According to the mass distribution law of bogie and car body (Table 3), the transmission of bogie and vehicle, the transmission of tire and bogie, and the interaction between tire and rail surface, the model of bogie, vehicle and road model (Table 4) is built shown in Fig. 3, on the basis of fully considering the force of the bogie.
Due to the contact between the wheels and rail surfaces, the train's motion on a track creates complex dynamic phenomena in the train itself and in the track's superstructure, which generates noise and vibrations that propagate in the external environment.
The particular attention to these types of defects is due to the acknowledged link existing between the corrugation of the rail surface and the generation of noise and vibrations (the corrugation interests also the surface of the wheels and naturally leads to an exacerbation of the phenomenon, but this is not discussed in this paper).
Also in the case of perfectly smooth rail surface, this phenomenon appears as a consequence of the track discontinuities for the sleepers present (regularly spaced).
If (x p, y q ) and (x p, yq + 1) satisfy the determination of the rail boundary points in Eq. 3, the (x p, y q ) is the lower boundary point of the rail surface and the (x p, yq + 1) is the upper boundary point of the rail.
The second method, which involves the determination of the curve Percentage Exceedance, seems to be very interesting: in an easy way can be read the whole range of irregularities found on the rail surface, highlighting the one with higher rate of presence.
a Defect A. b Defect B. c Defect C. Because of the complex shape of rail surface defect, the single feature description parameter cannot describe the defect exactly and comprehensively.
Thus, [6] studied the stress and strain states of the rails through a model composed of the primary suspension of vehicle, half locomotive wheelset, one rail, rail pads, and ballast demonstrating the influence of rail surface on the oscillations of contact forces and stresses.
He et al. used the mean background subtraction algorithm to extract the rail surface defects, but the robustness of the algorithm was weak [9].
For validation, the CT results were compared with metallographic observations of the rail surface for all the defects and the vertical section when needed.
