Determination of the temperature sensitivity values of an inclined Bragg grating embedded in the internal structure of a composite material for building structures

Abstract

This paper presents an inclined Bragg grating embedded into the internal structure of a composite material for building structures in the form of a wooden beam. The elements were made from pine and oak wood and were subjected to experimental analysis to determine the strain distribution when a constant load was applied to the free end of the beam. A temperature loss method is proposed to eliminate temperature sensitivity in deflection analysis. In this case, the temperature values of the sensitivity of all sensitive elements of the inclined Bragg grating of 5 FBGs. Additionally, the FBG was encased in carbon fabric impregnated with epoxy resin to increase sensitivity and positioned at a clamping point where deflection was negligible. Temperature compensation was achieved by taking into account the temperature measured by the built-in FBG and the sensitivity of all five FBG deflection sensors. Additionally, constructing this form using the recommended sensory approach resulted in an assessment elastic contour for all analyzed beams, where the experimental results coordinated with theoretical analysis, and exceeded 0.87 in all analyzed cases. Therefore, the proposed sensors represent a possible approach to reconstructing the shape of structural components in real time, with the advantages of being directly integrated into the structure being measured.