Demonstration of the detection of buckling effects in steel pipelines and beams by the distributed Brillouin sensor

We conducted the strain measurements to monitor steel pipe buckling for the first time using distributed Brillouin sensor system. Two specimens (steel pipeline and beam) were prepared by locally thinning the inner wall to provoke buckling. Fibre was laid along the external walls of the specimens. Strain gauges were glued in thinned wall area. An axial load was applied to the specimens and increased while compressive strain was measured by both Brillouin sensor and the strain gauges. The Brillouin sensor measurements showed the convolution of the all the strain distribution within the spatial resolution, the fitting Brillouin peak corresponds to the average strain over the spatial resolution, hence its reading can be smaller than the strain gauge reading depending on the location. With the Brillouin sensors, we observed compression in the whole specimens while elongation was detected in the neighbourhood of the thinned wall at onset of the buckling for the first time. The buckling was identified and localized with the Brillouin sensor measurement

Detection of buckling in steel pipeline and column by the distributed Brillouin sensor

We conducted a strain characterization experiment to monitor steel pipe and column buckling for the first time using a distributed Brillouin sensor system. Two specimens (steel pipe and column) were prepared by locally thinning the inner wall to initiate buckling. An axial load was applied to the specimens and increased while compressive strain was measured by both Brillouin sensor and strain gauges. With the Brillouin sensor, we observed compression on the whole specimens while elongation was detected in the neighborhood of the thinned wall at onset of the buckling. Both tension and compression are measured simultaneously from the same spectrum. This capability to extract both informations at the same time makes the Brillouin sensor a unique tool for structural health monitoring. The buckling was identified and localized thanks to this original approach

Pipeline buckling detection by the distributed Brillouin sensor

We conducted strain characterization experiment to monitor steel pipe buckling for the first time using distributed Brillouin sensor system. One specimen was prepared by locally thinning the inner wall to initiate buckling. An axial load was applied to the specimen and increased while compressive strain was measured by both Brillouin sensor and the strain gauges. With the Brillouin sensors, we observed compression in the whole specimen while elongation was detected in the neighbourhood of the thinned wall at onset of the buckling for the first time. The buckling was identified and localized with the Brillouin sensor measurement