Weldable fibre Bragg grating sensors for steel bridge monitoring

Abstract

For applications related to the structural health monitoring of steel bridges, novel weldable strain and temperature sensors based on fibre Bragg gratings were developed. These sensors, which can be directly welded to metallic structures, reveal linear responses over typical required measurement ranges and stability over thousands of load and temperature cycles. Proper installation procedures and in-field mechanical protection were also developed and implemented. The significance of the developed sensors was demonstrated through the installation of a complete sensing network on a new circular pedestrian bridge in Aveiro, Portugal, where it was used for loading tests, and also for in-service monitoring of its structural health.

Experimental study on pullout performance of sensing optical fibers in compacted sand

“…The installation of distributed strain sensing fibers in ground soils is a challenging task as compared with similar tasks in structural monitoring [19][20][21][22]. In most cases, the harsh and variable site environment and tight construction schedule do not allow a decent and elaborate installation program.…”

Global overview on advances in structural health monitoring platforms

“…The increasing advances on SHM have contributed for the broadening of the assessment process in a wide variety of structures [6,35,101]. With lower-cost systems development, SHM systems tend to be popularized [102] and integrated with other management systems, as security and comfort system, for instance.…”

Real Time Monitoring of Railway Traffic Using Fiber Bragg Grating Sensors

“…FBGs are very small, short-length single-mode fiber devices that display a periodic refractive-index variation in its core [7], [9]. When a broadband light transmits through the optical fiber, the FBG written in the core reflects back a wavelength ( ) depending on the Bragg condition =2n e where n e is the effective refractive index of the core and is the grating period.…”

“…It was also shown that FBG-based sensing systems could be used as axle counters and imbalance detectors. In [6] and [7] the FBGs were used to assess railway bridges. In this work we report on some tests using FBGs for dynamic load measurements in high-speed conditions (>200 km/h).…”