Temperature-compensated fiber Bragg grating sensor based on curvature sensing for bidirectional displacements measurement

Measurement of displacement, deformation, curvature, and other physical parameters is of great importance for adequate Structural Health Monitoring (SHM) of large surfaces. Fiber Bragg Grating (FBG) sensors have become a focus of research in academia and engineering for structural monitoring applications. This paper presents the study and characterization of a displacement FBG sensor based on curvature sensing of an array of 4 FBGs, as well as possible applications for structural monitoring, developing the sensing part, and analyzing the signals ob-tained to develop a sensor with good sensitivity and resolution, capable of measuring bidirectional displace-ments. The sensor prototype is presented to measure displacements in a range of +/- 30 mm with a single grating, with a sensitivity of up to 74 pm/mm, linearity to R2 = 0.999, and hysteresis error up to 1.27 %, with tem-perature compensation for displacement monitoring in case of temperature variations.