Distributed on-line monitoring system for deformation and fracture of fiber rail

In the railway transportation system, the rail plays the role of supporting the train and guiding the wheels of the vehicle. If there is a rail fracture, it may cause a train derailment, overturning and other major traffic safety accidents, resulting in casualties and huge property losses. Therefore, more and more attention has been paid to the detection of rail damage.

    At the same time, with the development of national high-speed railway and heavy-duty railway, the degree of rail extrusion and impact is increasing, and the probability of rail damage is also increasing. Therefore, in order to ensure the operation safety of high-speed railway and heavy duty railway, rail crack detection has become a very important thing for railway operation departments.

Schematic diagram of optical fiber real-time track breaking monitoring

Advantages of the system:

Optical fiber is not only the transmission medium, but also the sensing element. Because of the small transmission loss of optical fiber, it can realize the measurement of dozens or even hundreds of kilometers. Because of the use of optical signal as the carrier, free from electromagnetic interference, intrinsically safe, long service life, suitable for working in harsh environment

As a sensor, optical fiber body has strong anti electromagnetic interference ability, small size, light weight, simple structure, strong multiplexing ability, long transmission distance, corrosion resistance, high sensitivity, etc.

Technical features:

    Optical fiber real-time track breaking detection technology is a technical method to detect the stress using standard optical fiber attached to the track. By connecting one end of the optical fiber to the light source of the transmitting host, when the rail breaks or deforms, the internal waveform of the optical fiber will change accordingly, so as to judge whether the rail breaks or the rail deforms, and make early warning

Performance index:

1、Working wavelength        1550nm±5nm

2、Fiber type        single mode

3、Maximum dynamic range     15dB

4、Strain distance resolution    1m

5、Ranging accuracy ± (0.2 + 2 × sampling interval + 2 × 10-5 × distance) (m)

6、Strain test accuracy ± 0.005% (10-20ns) ± 0.001% (50-200ns)

7、Repeatability of strain test    ≤±0.01%

8、Strain test range     -1.5%～+1.5%

9、Test range         0.5、1、2、5、10、20、40、80km

10、Test pulse width         10、20、50、100、200ns