Longitudinal strain monitoring of rail using a distributed fiber sensor based on Brillouin optical correlation domain analysis

• Published in: NDT & E international : independent nondestructive testing and evaluation 2011-11, Vol.44 (7), p.637-644
• Main Authors: Yoon, Hyuk-Jin, Song, Kwang-Yong, Kim, Jung-Seok, Kim, Dae-Sang
• Format: Article
• Language: English
• Subjects: Applied sciences; Brillouin optical correlation domain analysis; Brillouin scattering; Brillouin zone; Correlation analysis; Exact sciences and technology; Fiber optics; Industrial metrology. Testing; Longitudinal rail strain; Mechanical engineering. Machine design; Monitoring; Non-destructive testing: methods and equipments; Nondestructive testing; Optical fiber sensor; Optical fibers; Rail monitoring; Rails; Strain
• ISSN: 0963-8695; 1879-1174
• DOI: 10.1016/j.ndteint.2011.07.004

A fiber-optic distributed sensor system is configured to measure the longitudinal strain distribution of a rail in real time. The system is based on the Brillouin correlation domain analysis (BOCDA), in which the variation of local Brillouin frequency ( ν B ) is measured that linearly depends on the strain applied to the optical fiber. In the test measurement, the longitudinal strain distribution along a 2.8 m rail is measured under different loading conditions with a spatial resolution of 3.8 cm and an accuracy of ±15 με. ► A distributed fiber sensor system for the railway rail is proposed. ► The system is based on the Brillouin correlation domain analysis. ► The longitudinal strain distribution of the rail was measured in real time. ► The spatial resolution of the strain measurement was 3.6 cm along the rail.