A Comparative Analysis of Fibre Bragg Grating Sensor and Conventional Electrical Strain Gauge Model for Structural Health Monitoring

Abstract

This research work presents a comparative analysis of Fibre Bragg Grating (FBG) sensor model and the conventional Electrical Strain Gauge (ESG) model for Structural Health Monitoring (SHM). SHM have been mainly deployed in telecommunication facilities owing to their exceptional ability to monitor infrastructures in hazardous environment. In this research, the FBG sensitivity was compared with that of the ESG sensor at different strain and stress values, at Poisson’s ratio ( ) of 0.19525 and 0.3, at effective refractive index (neff) of 1.44 and 1.5, and Gauge Factor (GF) of 1.1 and 1.5 respectively. FBG (A) is the FBG sensor with Poisson’s ratio of 0.3 and effective refractive index of 1.44, while FBG (B) is the FBG sensor with Poisson’s ratio of 0.19525 and effective refractive index of 1.5. The simulation result shows that FBG(A)performs better than FBG(B)by, 7.25% and 8.05% increment in sensitivity strain and stress. Also, 2.7% increment in sensitivity for ESG was achieved for induced strain and stress values on the composite structure at GF of 1.1 and 1.5 respectively. Additionally, it was observed from the obtained results that there exists a linear relationship between the FBG and ESG sensors. This observation shows that the FBG sensor can perfectly replace the conventional ESG sensor in SHM, in view of the additional advantages of the FBG sensor which are small size, immune to electromagnetic interference, light weight just to mention a few over ESG sensor.