Wheel-Rail Contact-Induced Impact Vibration Analysis for Switch Rails Based on the VMD-SS Method

Area of Science:

• Railway engineering
• Vibration analysis
• Structural health monitoring

Background:

• Damaged switch rails cause unsteady wheel-rail contacts, leading to impact vibrations that threaten train safety.
• Non-stationary vibrations from complex rolling contact excitations complicate the extraction and analysis of impact vibrations.

Purpose of the Study:

• To propose and validate a novel method for extracting impact vibrations caused by rail head damage.
• To improve the analysis of wheel-rail contact states and enhance structural safety in railway systems.

Main Methods:

• Utilized variational mode decomposition (VMD) to decompose impact vibrations into stationary intrinsic mode function (IMF) components.
• Applied spectral subtraction (SS) for further filtering of impact vibrations.
• Employed time domain feature analysis to estimate wheel passage moments and correct vehicle velocities.

Main Results:

• The proposed VMD-SS method effectively extracts impact vibrations from damaged rails, even in low-velocity scenarios.
• Frequency features of impact vibrations were concentrated in the 3500-5000 Hz range.
• Impact vibration frequency and peak-to-peak amplitude increased with higher excitation velocities.

Conclusions:

• The VMD-SS method provides a robust approach for analyzing impact vibrations in railway systems with damaged rails.
• Accurate extraction of impact vibrations aids in assessing structural integrity and preventing potential failures.