Experimental feasibility demonstration of steel structures monitoring using Fiber Bragg Grating technology

Although several fiber Bragg grating based transducers have been successfully applied to the measurement of strain and temperature in civil engineering applications, important research work must be done to obtain feasible and simple transducers which could be used in real installations. One of these research topics is the study of the measurand optimal transference between the structure and the sensing fiber through the tranducer holder. In the first part of this work, a wide range of fixing techniques and interface materials have been tested. This was achieved by fixing developed FBG based transducers to steel bars. These bars were strained while they were monitorized with conventional strain gauges and professional displacement sensors. Strain transference behaviour was characterized for each transducer type and optimal transducer structures were obtained. After that, steel girder flexural tests were designed and performed. In these tests, both sides of steel girder were monitorized with previously optimal FBG based transducers to characterize their tensional and compression behaviour. Conventional strain gauges where fixed to the steel girder to make comparisons between both technologies.