EXPERIMENTAL AND THEORETICAL RESULTS FOR STRAIN MEASUREMENT USING FIBER BRAGG GRATING SENSORS EMBEDDED INTO THE MATERIAL

The article presents the experimental results of the measurement of strains with fiber-optic strain sensors based on Bragg gratings embedded into the material. he following experiments were conducted: measurement of strains in a sample made of a polymer composite material with a stress concentrator, measurement of process-induced strains during the formation of a polymer composite material, measurement of process-induced strains during the curing of a cement mixture in the manufacture of concrete, and measurement of creep strain in a polymer material. In addition to the experiments demonstrating the possibility of measuring strains with fiber-optic strain sensors based on Bragg gratings embedded into the material, the results of a numerical analysis of the problems arising from the use of these sensors are presented. The analysis of the redistribution of the stress-strain state resulting from the embedding of an optical fiber into the material and the reliability of the strain values calculated on the basis of physical quantities obtained using sensors are among these problems.