Railway track degradation: The contribution of a spatially variant support stiffness - Global variation

Publication date: Available online 28 September 2019Source: Journal of Sound and VibrationAuthor(s): Mehran Sadri, Tao Lu, Michaël SteenbergenAbstractThe effect of large-scale variation in the support stiffness on railway track degradation is studied using a frequency-domain approach. The model used can deal with parametric excitation due to both the discrete sleeper spacing and arbitrary large-scale spatial track non-uniformity. Adopted stiffness profiles are based on realistic datasets in the literature. The sensitivity to degradation is assessed by quantifying the energy dissipation in the substructure over the influence zone. Results show that the effect of spatial stiffness variation generally increases with the speed, for any subgrade condition; system resonance however leads to increased degradation at resonance speeds and increases with the mean value of the track stiffness. The speed is shown to have a larger influence in the presence of non-uniformity than it has for uniform track with a mean value of the same non-uniform track stiffness, independent of this mean value. In general, support stiffness non-uniformity and poor track conditions (in terms of a low overall stiffness) may have comparable effects; the combination of both is a worst-case scenario. Predictions are independent from the randomness for measured datasets and have therefore general validity. Further, an excellent correlation is found between the spatial variation of the dynamic track stiffness, th...

Source: Journal of Sound and Vibration - September 29, 2019 Category: Physics Source Type: research