Effect on strength due to optical fibre embedding in advanced composites during structural health monitoring
The influence of embedded optical fibre on the strength of flexurally loaded composite laminate is studied in this paper. In a given structure, different loads create a complex state of stresses in the structure. In-situ structural health monitoring of composite structures could be achieved by using embedded optical fibre as sensors. The primary goal of this research is to assess whether the inclusion of optical fibre creates a local stress concentration which could trigger delamination and final collapse of the structure. In the current study optical fibres are embedded in three types of specimens; first at the neutral axis (50% thickness) and second at 75% thickness from the mould surface and at last without optical fibre. The resin rich area is around the optical fibre and the bonding between the optical fibre and the resin is studied using Scanning Electron Microscope (SEM). An attempt is made to assess the structure using C-Scan method. It was concluded that the embedded optical fibres could be successfully used as sensors in composite laminae and will not significantly compromise the strength and integrity of the composite host.