Inline Measurements of Rail Bending and Torsion Through a Portable Device
Structural condition of railway track can be quantified by considering the deflection of the track under load, since it is related to system stiffness. However measuring track deflection and torsion in working conditions represent a challenging task. In the present paper, the design and testing of a portable device for assessing rail bending and torsion as well as the relative wheel-rail position is presented. The proposed portable device is based on laser sensors, since they do not require any operations on the rails (contactless sensors) and allow placing the sensors at a reasonable distance from both the rail and the passing by wheel. The first bending eigenfrequency of the device is above 100 Hz in order not to dynamically amplify rail bending motions. Moreover the device can be easily mounted on different track sections in order to assess also the influence of vehicle type and speed. The portable device was used to measure rail banding and torsion during tests performed on a dedicated test track in Czech Republic both at low speed (20 km/h on a 150 m radius curve) and at medium speed (90 km/h on a 600 m radius curve) with two axle and four axle wagons. Installation was extremely easy and acquired signals were post-elaborated to assess rail vertical and lateral bending as well as torsion.
KeywordsPortable device Rail bending and torsion monitoring Contactless sensors Inline measurements
The authors wish to kindly acknowledge the European Community for having funded this research project (7th Framework Programme-Transport) and all other partners of the EU Project D-RAIL (Development of the future rail freight system to reduce the occurrences and impact of derailment), especially the partners involved in task 6.1 (Analysis of tests for the validation of numerical simulations).
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