Applications of Distributed Fibre Optics Sensing to Railway Industry

Abstract

Distributed Fibre Optics sensing was known for the last three decades, but it has been only recently, during the last 15 years, after the discovery of high spatial resolution sensing, when different industrial applications have been demonstrated in aeronautics, civil engineering, and also for transport and railway applications. Within this technology, a plain optical fibre is sensitive at each point of its length to strain/temperature changes, and consequently, it will detect a crack crossing the path of the optical fiber, as a very high spot for strain concentration. After introducing the physical principles and different approaches, their performances will be compared, and examples of real case applications will be shown. Most of the existing researches have addressed the measurement of strains at the rail track, to monitor the moving loads, and also the movements of the supporting ground, particularly the occurrence of sinkholes. Less common are those applications at which the optical fibre and the interrogation system are mounted on the carriage itself, to determine its structural integrity. Lecture concludes with ongoing developments in Europe, particularly for high speed trains.