Structural health monitoring for smart composites using embedded FBG sensor technology

Fibre-optic Bragg grating (FBG) sensors have been recognised as one of the smart localised and globalised structural health monitoring devices for many structural applications. A particular interest has been placed on embedding these sensors into advanced composites for in situ manufacturing process monitoring and then, lifetime structural health monitoring (SHM). There is no doubt that the need of maintaining structural integrity of these composites has been increased owing to an increasing use of carbon and glass fibre composites in real life structural and engineering applications. In the public transportation, the structural components of Airbus 350 XWB and Boeing 787 are made by over 50% of composite materials to replace traditional aluminium alloys. Electric vehicles have used lightweight carbon fibre composites as their chassis to overcome the weight penalty from batteries. With the advantages of high specific stiffness to weight ratio and good damping properties of polymer based composites, these composites are also used to reinforce and strengthen civil concrete structures that are located on the earthquake zones. In some critical engineering components, glass fibre composites with embedded shape memory alloy (SMA) wires are used for stiffness and shape controls during marginally operational conditions. Therefore, developing better SHM technologies is an urgent need to ensure the structural integrity and safety of structures. In this paper, FBG sensors for different SHMs are introduced and discussed. The use of the sensors with appropriate design for smart composites with sensing and actuating capacities is also presented.