Laboratory evaluation of fiber-optic sensors for strain monitoring

This paper presents laboratory experimental results on new Fabry-Perot fiber-optic sensors to verify their behavior and applicability for strain monitoring of engineering materials and structures. The research program consisted of thermal tests, tensile tests, and flexural tests. Two types of Fabry-Perot fiber-optic sensors were investigated and compared to electrical resistance strain gauges and fiber Braga gratings. Experimental results show that Fabry-Perot fiber-optic sensors perform linearly in monitoring tensile and compressive strains of infrastructure elements, and demonstrate good response to thermal variations and static and dynamic loading conditions. The fiber-optic sensing technology shows an enhanced accuracy and has potential for significant improvement in long-term strain monitoring over conventional strain gauges in field applications.