The mechanical load transfer into a distributed optical fiber sensor due to a linear strain gradient: embedded and surface bonded cases

Abstract

For an optical fiber sensor capable of distributed measurements, the elastic transfer between a substrate and the sensor itself is investigated. The degree to which a strain gradient in the optical fiber sensor reflects an existing strain gradient in the substrate is analysed for both the embedded and surface bonded optical fiber installations. The material and geometric parameters on which the strain transfer depends are described and a method by which the quality of strain transfer can be qualitatively assessed is proposed. Results include charts which may be used to predict the expected quality of gradient transfer.