Rail corrugation is a problem extensively felt by railway companies. This phenomenon appears in the railhead by the form of ondulations.
There are two types:
Short wavelength rail corrugation (3-10 cm)
Long wavelength rail corrugation (10-100 cm)
Origins:
Dynamical mechanical interaction of the vehicle-track system as wear and various forces.
The corrugation brings a high and annoying levels of noise and vibration.
Noise makes travel uncomfortable for passengers.
Vibration reduces the rail and wheel lifetime.
If not early detected, and treated (grinding), the problems aggravate, and becomes more and more expensive treat the problem.
RailScan – Developed Tools
To detected and quantify rail corrugation a software tool was developed: RailScan. Data to process:
Axle-box or vehicle Accelerometer data
RailScan corrugation signal analysis includes:
Classical Spectral Analysis
One Third Octave Filter power representations
Time-scale representation with user selected wavelets Wavelet-Packet implementation that results in power spectrum in the corrugation
Wavelengths
Rail corrugation localization in the rail and its signal recovering in selected wavelet nodes
Why Wavelets?
Wavelet analysis generally outperforms the classical spectral methods for non-stationary signals such as the rail corrugation data, namely in data affected by noise.
In recent times Wavelet analysis has been successfully applied to similar signals, and seems to be the adequate tool for these signals. However there is a great deal of research work in order to validate these methods.