Chapter 25 - Structural Strain and Temperature Measurements Using Fiber Bragg Grating Sensors

Abstract

Fiber Bragg grating (FBG) sensors have been the subject of intense research and development since the discovery of photosensitivity in optical fibers. This chapter reports some of the recent work on applying FBG sensors for structural strain and temperature measurements, including (1) internal strain measurement of composite strengthened concrete bars, (2) dynamic strain measurement of composite materials by using embedded sensors, (3) simultaneous measurement of fluctuating and average temperature of structures in cross-flow, and (4) static and dynamic strain measurement of a train body-shell during static and dynamic load test. These applications make use of the unique features of optical fiber sensors such as small size, and hence these sensors are suitable for embedding, immune to electromagnetic interference, and have remote sensing and multiplexing capability.The FBG sensors give better results than their electric counterparts, because of their unique features such as small size and ruggedness.