SENSITIVITY COEFFICIENT EVALUATION OF AN EMBEDDED FIBEROPTIC STRAIN SENSOR

A simple model is developed for evaluating the interaction between the surrounding matrix and a length of optical fiber embedded in it. The analysis has been performed for nominal uniform pull-stress applied to the matrix, in which a sensitivity coefficient K(L) is used to descri be the percentage of strain applied to the composite actually transfer red to the fiber. The theoretical results have shown that the sensitiv ity coefficient of the fiber-optic strain sensor depends on the embedd ed length of the optical fiber and the material properties of the fibe r coating. The general trend of increasing the sensitivity coefficient with increasing action length has been confirmed by the experimental results. The distributions of interfacial shearing stress between matr ix and coating and coating and glass fiber are given. Experiments have been performed using a white-light fiber-optic interferometer. (C) 19 98 Elsevier Science S.A. All rights reserved.