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

• Measurement of large surface displacements is crucial for SHM. • Characterization of an FBG displacement sensor based on curvature sensing is presented. • Bidirectional displacement measurement is possible with high sensitivity. • Temperature compensation technique reduces contributions due to fast temperature changes. 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 obtained to develop a sensor with good sensitivity and resolution, capable of measuring bidirectional displacements. 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 R 2 = 0. 999, and hysteresis error up to 1.27 %, with temperature compensation for displacement monitoring in case of temperature variations. [ABSTRACT FROM AUTHOR]