Distributed Strain Monitoring of Railway Composite Bogies Using a Brillouin Optical Correlation Domain Analysis System

Abstract

The structural deformation of a bogie frame manufactured using a composite material was monitored in real time using a distributed optical fiber sensor. The bogie frame contained an internally embedded standard single-mode optical fiber. Performance tests were conducted by applying a vertical load to the middle of the side beams on each side of the composite bogie frame. The strain distribution was monitored using an optical fiber sensor. A distributed optical fiber sensor system based on the Brillouin optical correlation domain analysis (BOCDA) technique with a 3 cm spatial resolution was used. The distributed strain measured using the optical fiber correlated well with the finite element (FE) analysis data, confirming that the composite bogie frame was fabricated as designed. For a vertical load of 182 kN, the maximum strain, which occurred in the middle of the side frame, increased by 1.3 times, as compared with a vertical load of 140 kN. The experiment was able to verify the balance and the structural stability of the left- and right-hand-side beams. Furthermore, it could confirm that there was a concentrated load where the side beam and the crossbeam meet, owing to a mismatch during the assembly of the composite bogie frame.

Recent advancements in the applications of fiber‐reinforced polymer structures in railway industry—A review

“…Further investigations on the dynamic properties of the composite bogie frame showed that even by eliminating the primary suspension system in the composite frame, dynamic wheel unloading, wheel wear index, and ride comfort satisfy the design requirements 24,31 . More recently, distributed optical fiber sensors were employed to monitor the structural deformation of the developed composite bogie in real‐time 32 . The presented monitoring method, represents a viable way for a real time evaluation of the composite structure's health status.…”

“…24,31 More recently, distributed optical fiber sensors were employed to monitor the structural deformation of the developed composite bogie in real-time. 32 The presented monitoring method, represents a viable way for a real time evaluation of the composite structure's health status. This system makes it possible to determine whether delamination or cracks in composites happen during running time of the bogie.…”

Brillouin Frequency Shift Sensing Technology Used in Railway Strain and Temperature Measurement

“…The above mentioned BFS sensing method had been used in railway composite bogies [8] and railway bridge [9] measurement.…”