Curvature Sensor Based on FBGs Embedded in 3D Printed Patches

In this paper, a novel curvature sensor, is showed. The proposed sensor is based on two FBGs, properly embedded in a 3D printed patch: the FBGs measure the strain in two point at a different distance from the monitored structure and the curvature of the structure under test is estimated from the difference in their strain. The simple and compact sensor exhibits a curvature sensitivity of 1.39 nm/m
⁻¹
with a resolution equal to
$7.2\cdot 10^{-4}\,\,\text{m}^{-1}$
. The curvature test shows a very excellent agreement between the curvature recorded with the new sensing device and that of the reference sensor. Neutral axis position of the monitored structure can be also estimated with this sensor.