Bend Sensor Using Fiber Bragg Gratings to Determinate the Distance from the Sensor to the Neutral Axis in Compression and Extension

The following paper presents a bend sensor that consists of three Bragg Gratings inside a Standard Fiber Optic for the characterization of the reflected wavelengths with respect to the radius of curvature in conditions of compression and extension, and it is used to determinate the distance between the bend sensor and the neutral axis. This necessity is because there are many problems with the packaged and the union techniques of the bend sensor and the surface that will be sensed. Knowing this distance is possible to distinguish the behavior in compression and extension of a unique way, because for different sensor positions with respect the neutral axis and with a same value of radius of curvature, there will be different reflected wavelengths, but it will be possible to determinate the real radius of curvature using different distances.