Residual Stress in a Polymer-Glued FBG Temperature-Compensated Sensor for Civil Engineering Applications

Abstract

In recent years, embedded fibre-optic sensors as structural health monitoring devices have been widely used in both civil and aerospace engineering applications. Their small physical size and ability to immunize electromagnetic interference make them ideal sensing devices, which provide highly accurate and reliable strain and temperature measurements for structures. This paper presents a new designed temperature-compensated fibre-optic Bragg grating (TCS) strain sensor for imbedding into cement-based materials to measure their mechanical and thermal strains individually or simultaneously. However, the residual stress generated due to the constrained boundary of a steel tube that is used to protect the sensor, will influence the accuracy of measurement. Therefore, a theoretical model that is used to estimate this stress at different temperature conditions is discussed.