Stress–Strain Response of Optical Fibers in Direct Tension

Abstract

Stress-strain response of optical fibers in direct tension is introduced in this article. The research involved direct tension tests of optical fibers and development of theoretical relationships describing the tensile behavior of the fibers. Two types of optical fibers, namely ribbon and standard single mode fiber (SMF-28) were included in the experimental and theoretical investigations. The impetus for the study was the need for the elastic properties of the optical fibers, such as the modulus of elasticity and the elastic limit for accurate interpretation of strains measured by optical fiber sensors. Ribbon fibers have proven to be robust for sensing applications in civil structures which prompted the research described herein. By employing the experimental data and by using the generalized Ramberg-Osgood law, it was possible to establish the theoretical stress-strain responses of the optical fibers. The experimental program allowed for distributed measurement of optical fiber strain by a Brillouin Optical Time Domain Analysis system (BOTDA). These results were compared with the direct measurement of the applied displacements at the fiber ends.