Damping effects on vibrations of railway prestressed concrete sleepers

Railway concrete sleepers have been generally used in ballasted railway track around the world for over 50 years. They are commonly used to redistribute wheel forces onto track structure and to assure stable track gauge for safe passages of rolling stocks. The dynamic behaviours of railway sleepers are commonly well known; however, its damping characteristic is often neglected. With the increased demand for heavier and faster trains, the nature of track forces applying onto each track components is no longer static or quasi-static. Statistically, almost a quarter to track load spectra is typically of transience and high intensity. The ignorance of damping can no longer be persisted as pre-mature damage or failure of track components can take place at a faster rate. A single sleeper failure may not affect open, plain track operations but it can give rise to the risks of rail breaks at rail joints, welds, bridge ends, switches and crossings, curved track, etc. Such the risks can later result in detrimental train derailments. This is thus very important to consider the failure of sleepers in a case by case basis that is suitable for the track type, track condition and level of maintenance and operations. This paper will highlight the effects of damping on the vibrations of railway concrete sleepers in a track system. An established and validated finite element model of sleeper has been adopted for further studies. The model has been validated by experimental results. This study aims to quantify the potential to improve damping in concrete in order to suppress vibrations in a track system. The insight into the vibration suppression of railway sleepers will help track engineers to decide the better choice of advanced materials for manufacturing railway concrete sleepers.