Long Gage Fiber Optic Bragg Grating Strain Sensors to Monitor Civil Structures

Fiber optic Bragg gratings packaged in long gage configurations are being used to measure static and dynamic macro-strains in structures and structural models to monitor structural health and detect and identify macrodamage incurred from a seismic event. These long gage sensors are being used to experimentally verify analytical models of small-scale structural models in their preand post-damage states using system identification techniques. This fiber optic deformation measurement system could play a significant role in monitoring/recording with a higher level of completeness the actual seismic response of structures and in nondestructive seismic damage assessment techniques based on dynamic signature analysis. This new sensor technology will enable field measurements of the response of real structures to real earthquakes with the same or higher level of detail/resolution as currently in structural testing under controlled laboratory conditions.