Damage detection method for sleepers based on vibration properties

Abstract

In order to detect the damages of PC sleeper in the ballast track which cannot be inspected visually, the damage detection method using vibration mode characteristic of PC sleepers was developed. As a result of the vibration measurement test that conducted in parallel to the bending test, it was confirmed that natural frequencies begin to decrease when more than 1.2 times of the cracking load acted. In Addition, as the results of measurements PC sleepers with actual damages and measurements at the full-scale test rail line, 3rd mode natural frequency in which the effect of damage appears greatly and the variation of ballast does not affect is a suitable indicator for detection of the cracks. Furthermore, focusing on the application on the routine patrol, the high workability damage detection by single point measurement and simple signal processing was considered. As a result, it can be confirmed that the same detection accuracy as the damage detection based on the multipoint measurement was securable.