INVESTIGATION OF RAILWAY TRACK MODAL BEHAVIOUR

Abstract

Network Rail (NR) manages the railway infrastructure in Great Britain. Their roles include managing tracks, bridges, station and signalling. With increasing demands on rail services, NR continually strives to provide reliable and safe railways by improving their inspection and maintenance methodologies. In this project, modal analysis has been utilised to investigate the behaviour of the rail track under vibration by building a model representing the rail track using Finite Element Method (FEM). The rail profile 56E1 was used in this study for the two cases (healthy and damaged rail) in the free-free boundary condition. The purposed model has been validated experimentally in the laboratory. The two results were in good agreement. The modal analysis technique was used in support of inspection and detection tools. The response of the rails in the case of a healthy and damaged rail was tested and compared by analysing the change in the natural frequency. It is found that the first three vibration modes are sufficient to detect cracks. It is also observed that the change in the natural frequency of the rail is a function of the crack depth. When the crack depth increases the natural frequencies of the rail decreases. Based on the obtained results, modal analysis was found to be promising in monitoring the integrity of the rail and can be possibly utilised as an inspection tool using autonomous vehicles provided with a laser vibrometer.