Embedded FBG sensors for structural health monitoring of advanced composite structures

Embedded FBG sensors for structural health monitoring of advanced composite structures

Fibre reinforced polymer composite materials (FRP) have been used in critical civil infrastructure for several decades due to their attractive strength to weight ratio and ease of manufacturing to meet required design objectives. However, the long-term behaviour of FRP structures is not well understood and the fear of catastrophic failure inhibits the wide-spread use of them. Frequent monitoring, therefore, is essential in order to know the structural integrity and damage status of the structure to give early warning signs. Recent developments in sensor technologies have significantly contributed to the improved health monitoring systems for critical infrastructure. Among those new generation sensors, Fibre Bragg Grating (FBG) sensors have demonstrated their superior properties in Structural Health Monitoring (SHM) of composite structures. This thesis details a conceptual design and application of an embedded FBG sensor network in a representative FRP bridge deck structure and a representative hybrid FRP bridge beam. Sensor embedding methods were developed that save production time and improved the durability of the sensors. The smart deck was tested under Uniformly Distributed Loads (UDL) with increasing simulated damage to show the FBG sensor ability to detect damage. The smart bridge beam was tested under cyclical four point bending and successfully showed FBG sensor ability to detect early signs of fatigue.